- Privacy Guides added SimpleX Chat to the recommended private and secure messengers.
- Mike Kuketz – a well-known security expert – published the review of SimpleX Chat and added it to the messenger matrix.
@@ -440,9 +440,9 @@ window.addEventListener('scroll',changeHeaderBg);
The new version does not allow them by default, but it can be enabled by group owners in the group settings when the group is created or at any later moment.
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
-Technical details and limitations.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
+Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see the information on our new website - it also answers all these questions.
Help us with donations
diff --git a/blog/20230103-simplex-chat-v4.4-disappearing-messages.html b/blog/20230103-simplex-chat-v4.4-disappearing-messages.html
index 2673134399..6592e6e500 100644
--- a/blog/20230103-simplex-chat-v4.4-disappearing-messages.html
+++ b/blog/20230103-simplex-chat-v4.4-disappearing-messages.html
@@ -391,7 +391,7 @@ window.addEventListener('scroll',changeHeaderBg);
Disappearing messages
It is now possible to send the messages that will be deleted from both sender and recipient device after set time – for the sender from the time they were sent, and for the recipient - from the time they were read.
-Unlike in most other messengers, it requires agreement of both sides, not just the sender decision. I wrote previously why we believe it is wrong to allow the senders to delete their messages without recipient consent, and the same logic applies here – if you want to send the message that will disappear after some time, your contact should be ok with that too.
+Unlike in most other messengers, it requires agreement of both sides, not just the sender decision. I wrote previously why we believe it is wrong to allow the senders to delete their messages without recipient consent, and the same logic applies here – if you want to send the message that will disappear after some time, your contact should be ok with that too.
In group conversations disappearing messages can be enabled by the group owners, by default they are disabled.
"Live" messages
@@ -411,8 +411,8 @@ window.addEventListener('scroll',changeHeaderBg);
Please get in touch if you want to translate the interface into your language!
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html b/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html
index c032bd615b..308670b6a4 100644
--- a/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html
+++ b/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html
@@ -434,8 +434,8 @@ window.addEventListener('scroll',changeHeaderBg);
You can contribute the translation of the apps to your language too!
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20230301-simplex-file-transfer-protocol.html b/blog/20230301-simplex-file-transfer-protocol.html
index 5f9104d6fc..3ee93359e8 100644
--- a/blog/20230301-simplex-file-transfer-protocol.html
+++ b/blog/20230301-simplex-file-transfer-protocol.html
@@ -462,11 +462,11 @@ file ---> | XFTP | ------> XFTP ----> | Rela
We are currently integrating support for sending large files using XFTP protocol into SimpleX Chat clients. SimpleX Chat v5.0 will have support for receiving files sent via XFTP protocol (you will be able to send a file description via a SimpleX Chat CLI app, so that mobile apps will be able to receive them as normal files, only much faster), and v5.1 will fully support for sending large files (up to 1gb) in the mobile apps.
We will also publish a formal specification for XFTP protocol and overview of its security qualities and threat model. For now you can learn more about the protocol design and motivations from this internal XFTP protocol RFC.
Using and sending files with the available XFTP CLI will hugely help us stabilizing both the protocol and implementations. What we really like about this design is that it is completely independent from SimpleX Chat - you can use it on its own, sending files and passing file descriptions to your contacts via any other messenger - e.g. via Signal, – without this messenger being able to observe that you are in fact sending a large file.
-We did not yet decide whether we will be making a separate security audit of XFTP implementation, or if we combine it with the next security audit of SimpleX Chat. The latter seems more likely, as XFTP uses the same cryptographic primitives that were reviewed during SimpleX Chat security assessment by Trail of Bits in November 2022.
+We did not yet decide whether we will be making a separate security audit of XFTP implementation, or if we combine it with the next security audit of SimpleX Chat. The latter seems more likely, as XFTP uses the same cryptographic primitives that were reviewed during SimpleX Chat security assessment by Trail of Bits in November 2022.
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20230328-simplex-chat-v4-6-hidden-profiles.html b/blog/20230328-simplex-chat-v4-6-hidden-profiles.html
index 4b484a108e..8a95daa4b4 100644
--- a/blog/20230328-simplex-chat-v4-6-hidden-profiles.html
+++ b/blog/20230328-simplex-chat-v4-6-hidden-profiles.html
@@ -428,7 +428,7 @@ window.addEventListener('scroll',changeHeaderBg);
The app now supports 8 languages in addition to English - Czech, German, Spanish, French, Italian, Dutch, Russian and Chinese. You can now choose the language via the app settings (Appearance page), independently from the system settings.
Some links to answer the most common questions:
-SimpleX Chat security assessment.
+SimpleX Chat security assessment.
How can SimpleX deliver messages without user identifiers.
What are the risks to have identifiers assigned to the users.
Technical details and limitations.
diff --git a/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html b/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html
index 7ff983bcd5..9ce820b819 100644
--- a/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html
+++ b/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html
@@ -402,7 +402,7 @@ window.addEventListener('scroll',changeHeaderBg);
Many large tech companies prioritizing value extraction over value creation earned a bad reputation for all businesses, particularly in the communities that value decentralization and privacy. But commercial objectives do not have to result in exploitation. Our goal is to build a new kind of communication network, and also an application platform, that is private by design, fully decentralized and not owned by any single entity, where SimpleX Chat Ltd is one of many organizations that operate the network. I shared my thoughts about how the Internet and privacy might evolve in the interview in Opt Out Podcast.
How is it funded and what is the business model?
We started working full-time on the project in 2021 when Portman Wills and Peter Briffett (the founders of Wagestream where I led the engineering team) supported the company very early on, and several other angel investors joined later. In July 2022 SimpleX Chat raised a pre-seed funding from the VC fund Village Global - its co-founder Ben Casnocha was very excited about our vision of privacy-first fully decentralized messaging and community platform, both for the individual users and for the companies, independent of any crypto-currencies, that might grow to replace large centralized platforms, such as WhatsApp, Telegram and Signal.
-Overall we raised from our investors approximately $370,000 for a small share of the company to allow the project team working full time for almost two years, funding product design and development, infrastructure, and also the security assessment by Trail of Bits. A large part of this money is not spent yet.
+Overall we raised from our investors approximately $370,000 for a small share of the company to allow the project team working full time for almost two years, funding product design and development, infrastructure, and also the security assessment by Trail of Bits. A large part of this money is not spent yet.
The project was hugely supported by the users as well - collectively, you donated over $25,000. Without these donations the investment we raised would not be possible, because we believe that voluntary user donations can sustain the project in the long term – it already covers all infrastructure costs. There are only two ways an Internet service can exist - either users are paying for it, or the users data becomes the product for the real customers, as happened with many large Internet companies. In the latter case the users are losing much more money than they are saving by giving away their privacy and the rights to the content they create on the centralized platforms.
Going forward we plan to keep the basic usage of the platform free, and at the same time we will be providing the benefits to the project sponsors. For example, there will be additional app icons and user profile badges. There also will be higher file transfer limits – currently we don't limit it at all, only limiting the file size, but it's unlikely to be sustainable. In any case, the app will remain highly usable for everyone for free, and fully open-source. Several other apps are already being developed based on our app core, leading to a fully decentralized network.
What is next?
@@ -410,14 +410,14 @@ window.addEventListener('scroll',changeHeaderBg);
- more reliable and resilient, by adding redundancy into the message delivery and delivery receipts,
- more private, by automating rotation of the servers used to deliver messages and by adding delivery relays to better protect IP addresses of the users,
-- more usable by adding and improving the functions users are expecting in messengers, and also adding some unique functions, like we did with incognito mode, live messages and hidden profiles.
+- more usable by adding and improving the functions users are expecting in messengers, and also adding some unique functions, like we did with incognito mode, live messages and hidden profiles.
One major initiative we will kick-off this year is the support for large, fully decentralized and private communities and groups not hosted on any servers – something that no Internet platform achieved so far in as private and efficient way as we plan to build it.
To accelerate product development and growth we will be raising a seed funding this year, both from the VCs and angel investors, and we also might offer our users an opportunity to participate in the crowd funding round on the same terms as other investors, allowing to both support the project and to benefit from its future growth. Subscribe to our updates not to miss it, connect to the team in SimpleX Chat and join users' groups.
What's new in v5.0
Send videos and files up to 1gb!
-In the beginning of March we released servers and command-line utility to send and receive files via XFTP protocol - a very private and secure protocol that sends end-to-end encrypted files in chunks, protecting meta-data better than any alternatives we know of.
+In the beginning of March we released servers and command-line utility to send and receive files via XFTP protocol - a very private and secure protocol that sends end-to-end encrypted files in chunks, protecting meta-data better than any alternatives we know of.
Now this protocol is fully integrated in SimpleX Chat, and all files except small voice messages are sent using this protocol (small voice messages are sent as usual messages). Not only it is much faster than before - with the fast Internet connection I can send 25Mb file in 3 seconds and 1gb file in 2 minutes (for most users it's capped at the available Internet bandwidth), it has two other major advantages making it more usable:
- the file sent to a group has to be uploaded only once, regardless of the group size.
@@ -437,7 +437,7 @@ window.addEventListener('scroll',changeHeaderBg);
Secondly, Android client now supports configuring host and port of the SOCKS proxy, allowing to use apps other than Orbot and also to run SOCKS proxy in the local network, to save mobile device battery.
Some links to answer the most common questions:
-SimpleX Chat security assessment.
+SimpleX Chat security assessment.
How can SimpleX deliver messages without user identifiers.
What are the risks to have identifiers assigned to the users.
Technical details and limitations.
diff --git a/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html b/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html
index 0b1d1548a9..4eb704432e 100644
--- a/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html
+++ b/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html
@@ -413,20 +413,20 @@ window.addEventListener('scroll',changeHeaderBg);
Improved messages
Voice messages: up to 5 minutes, better quality, playback control
-Since v4.3 voice messages were sent in small 16kb chunks, so we had to limit them to 30-40 seconds for better user experience, as sending larger files would require the sender to be online.
+Since v4.3 voice messages were sent in small 16kb chunks, so we had to limit them to 30-40 seconds for better user experience, as sending larger files would require the sender to be online.
With the new XFTP protocol that allows sending files up to 1gb it is now possible to increase the message size - we decided to limit it at 5 min, increasing their quality 2x (the bitrate is increased from 16 to 32kbps). We also added a slider to control the playback.
Disappearing messages: choose any time!
-Since v4.4 disappearing messages were only configurable for the whole conversation, with a limited choice of allowed times between 30 seconds and 1 month.
+Since v4.4 disappearing messages were only configurable for the whole conversation, with a limited choice of allowed times between 30 seconds and 1 month.
This version allows to configure the time for messages to disappear more granularly, in the range from 1 second to 3 months. You can also set a different time to disappear when you send the message (hold the Send button), as long as disappearing messages are enabled in the conversation.
Message editing history
-I wrote previously why we decided to require the recipient concent before the messages can be fully deleted by the sender - in short, it is to support recipient's data sovereignty and prevent the possibility of offensive messages being removed without any trace. By default, when the sender deletes the message it is marked as deleted, rather than fully deleted, and you can reveal the original message.
+I wrote previously why we decided to require the recipient concent before the messages can be fully deleted by the sender - in short, it is to support recipient's data sovereignty and prevent the possibility of offensive messages being removed without any trace. By default, when the sender deletes the message it is marked as deleted, rather than fully deleted, and you can reveal the original message.
You've found the workaround for it of course - it's enough to simply edit the message to hide the original content. This version adds a visible message editing history, together with other detailed information about when the message was sent, received or deleted, that wasn't visible in the conversation.
Customize and share color themes
Android app now allows choosing between three color themes - Light, Dark and SimpleX (a dark blue theme). You can customize any theme by setting 9 different colors used in the app, including titles, menus, accent colors and colors for sent and received messages.
-You can share your theme with other users by exporting it to a file and sending to them. You can also contribute your favorite themes to our GitHub repository.
+You can share your theme with other users by exporting it to a file and sending to them. You can also contribute your favorite themes to our GitHub repository.
Self-destruct passcode
This is something many of you asked before - when asked to enter the app passcode under duress, to be able to enter a special self-destruct code that would remove the app data. This feature is offered in many security tools, and now you can configure it in SimpleX Chat as well.
@@ -439,7 +439,7 @@ window.addEventListener('scroll',changeHeaderBg);
Some links to answer the most common questions:
-SimpleX Chat security assessment.
+SimpleX Chat security assessment.
How can SimpleX deliver messages without user identifiers.
What are the risks to have identifiers assigned to the users.
Technical details and limitations.
diff --git a/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html b/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html
index 774b2bf842..3ee4aa6ec4 100644
--- a/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html
+++ b/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html
@@ -422,7 +422,7 @@ window.addEventListener('scroll',changeHeaderBg);
Most messaging apps add two ticks to sent messages – the first one to show that the message is accepted by the server, and the second – that it is delivered to the recipient's device. It confirms that the network is functioning, and that the message is not lost or delayed. SimpleX Chat now has this feature too!
In some cases it may compromise recipients' privacy, as they show that the recipient is online, so we made sending delivery receipts optional – it can be disabled separately for each chat profile or contact. For the new chat profiles this feature is enabled by default.
-To avoid compromising your privacy, sending delivery receipts is disabled for all your existing chat profiles. The first time you start the app after the update, you will be offered to enable them for all visible profiles, and they can be enabled later via Privacy and Security settings.
+To avoid compromising your privacy, sending delivery receipts is disabled for all your existing chat profiles. The first time you start the app after the update, you will be offered to enable them for all visible profiles, and they can be enabled later via Privacy and Security settings.
Filter favorite and unread chats
You can now mark your contacts and groups as favorite, to be able to find them faster. With filter enabled, you will only see favorite chats, chats that contain unread messages and also any unaccepted group invitations and contact requests.
@@ -441,8 +441,8 @@ window.addEventListener('scroll',changeHeaderBg);
Please report the cases when messages are not delivered – delivery receipts should help with that.
Messages failed to decrypt? Problem solved!
Previously, a growing number of users had the issue when after restoring the chat database from backup, messages from some contacts failed to decrypt and were showing an error in the app.
-This happens due to double ratchet protocol protecting the integrity of end-to-end encryption after the compromise - post-compromise security. The protocol logic does not allow to use the old version of the database to decrypt the message.
-v5.2 added the extension to the messaging protocol allowing to negotiate the new ratchet keys in such cases - both with the contacts and the group members. This requires a user action, and it resets the security code verification status for this contact or member – you need to verify it again to have the additional protection from man-in-the-middle attacks.
+This happens due to double ratchet protocol protecting the integrity of end-to-end encryption after the compromise - post-compromise security. The protocol logic does not allow to use the old version of the database to decrypt the message.
+v5.2 added the extension to the messaging protocol allowing to negotiate the new ratchet keys in such cases - both with the contacts and the group members. This requires a user action, and it resets the security code verification status for this contact or member – you need to verify it again to have the additional protection from man-in-the-middle attacks.
The negotiation of the new ratchet keys still happens via the end-to-end encrypted messages, as the protocol has two layers of end-to-end encryption, so it cannot be compromised by the messaging relays.
You may still lose connection if you or your contact changed the receiving address after you made the backup, so make sure to make a new backup after any receiving address changes.
Reconnect the servers
@@ -462,12 +462,12 @@ window.addEventListener('scroll',changeHeaderBg);
Why not hosted groups with MLS?
Initially, we considered the design with the dedicated servers, potentially self-hosted, that host groups. This design would require adopting MLS (or similar) protocol for group-wide key agreement. Unfortunately, this design is not sufficiently resilient and easier to censor than decentralized design. Also, MLS protocol is very complex to implement, requires a centralized component, and reduces forward secrecy. So we decided against this approach.
Why not fully decentralized groups?
-We also considered rumour-mongering protocol, where all members are equal and participate in message dissemination. The problem with this approach is that it adds a lot of traffic for all members, even those who mostly read messages. Also, it still requires establishing a fully connected graph, and with large groups it becomes prohibitively expensive and unreliable, given that many members join public groups for a limited time.
+We also considered rumour-mongering protocol, where all members are equal and participate in message dissemination. The problem with this approach is that it adds a lot of traffic for all members, even those who mostly read messages. Also, it still requires establishing a fully connected graph, and with large groups it becomes prohibitively expensive and unreliable, given that many members join public groups for a limited time.
Members host the groups
We are now considering a middle-ground - the design where the owners and admins host the group, synchronising the state between them, receiving and re-broadcasting the messages between all members. This puts a higher burden on these members, but these clients can be hosted in the cloud, and also group owners have a larger incentive to maintain group integrity. At the same time, this design is better for the rest of the group members, as they don't need to establish connections with all other members, only with a limited number of "hosting" members, and it also better protects their privacy, due to the lack of direct connections between most members.
This approach avoids the need for a group-wide key agreement protocol, as hosting members are expected to have access to all content anyway, so pair-wise ratchets are sufficient. At the same time the content remains end-to-end encrypted, and protected from the outsiders.
This approach also simplifies moderation - the message that needs to be removed simply won't reach the members before it is moderated (in case of automatic or policy-based moderation).
-Discovery and content search in such groups will be provided via a dedicated discovery server that will participate in the group, provide an always-online client, and also automatic content moderation functionality - a possible approach to moderation is described here.
+Discovery and content search in such groups will be provided via a dedicated discovery server that will participate in the group, provide an always-online client, and also automatic content moderation functionality - a possible approach to moderation is described here.
We really look forward to your feedback on this design.
What about read receipts?
We have an approximately equal number of users who ask us to add receipts, and those who ask not to add them, even as optional.
@@ -477,7 +477,7 @@ window.addEventListener('scroll',changeHeaderBg);
There is also no discounting that the presense of read receipts functionality, even as opt-in, creates a social pressure to enable them, with the same consequences – there are many scenarios when they become non-optional in some relationships. So many users belive, and we share this view, that it is better not to have these features at all. We will be re-assessing this view.
Some links to answer the most common questions:
-SimpleX Chat security assessment.
+SimpleX Chat security assessment.
How can SimpleX deliver messages without user identifiers.
What are the risks to have identifiers assigned to the users.
Technical details and limitations.
diff --git a/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html b/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html
index 18798ca8f9..be0315a9c8 100644
--- a/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html
+++ b/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html
@@ -415,11 +415,11 @@ window.addEventListener('scroll',changeHeaderBg);
- you cannot send voice messages.
- there is no support for calls yet.
Directory service provides a way to search for public groups submitted by the users. To use it, you need to connect to it via SimpleX Chat, as you would connect to any other contact, and type some words to search.
-
@@ -436,7 +436,7 @@ window.addEventListener('scroll',changeHeaderBg);
All messages, files and media sent via SimpleX Chat were always end-to-end encrypted from the very beginning. SimpleX Chat uses double-ratchet algorithm with encrypted message headers, for the best possible meta-data protection.
-You contacts, groups and messages are stored in the local database on your device, and this database was encrypted from v4.0 released a year ago.
+You contacts, groups and messages are stored in the local database on your device, and this database was encrypted from v4.0 released a year ago.
But until this version all files and media in the app storage were not encrypted, and when you exported the chat archive, they were unencrypted there as well.
From v5.3 all files and media (except videos, for now) are encrypted with a random symmetric key - in many cases they are encrypted before they are written to the storage. Local file encryption can be disabled via Privacy & Security settings, for example, if you need to access the files from the storage outside of the app.
In addition to the videos that are stored unencrypted, there are other rare scenarios when the received files may be unencrypted in this release. Files have an open or closed lock icons to indicate whether they were encrypted locally. These limitations will be addressed in the next release. In any case, all files and media are always sent end-to-end encrypted, without any exceptions.
@@ -444,12 +444,12 @@ window.addEventListener('scroll',changeHeaderBg);
This approach provides forward secrecy for locally stored files, unlike file encryption schemes used in some other apps when the same passphrase is used for all files.
Simplified incognito mode
-Incognito mode was added a year ago to improve anonymity of your profile, but it was confusing for some users - it was a global setting, but it only affected the new connections.
+Incognito mode was added a year ago to improve anonymity of your profile, but it was confusing for some users - it was a global setting, but it only affected the new connections.
It is now simpler to use - you can decide whether to connect to a contact or join a group using your main profile at a point when you create an invitation link or connect via a link or QR code.
When you are connecting to people you know you usually want to share your main profile, and when connecting to public groups or strangers, you may prefer to use a random profile.
Some links to answer the most common questions:
-SimpleX Chat security assessment.
+SimpleX Chat security assessment.
How can SimpleX deliver messages without user identifiers.
What are the risks to have identifiers assigned to the users.
Technical details and limitations.
diff --git a/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html b/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html
index 1ae19ee3bc..fc442eb3b4 100644
--- a/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html
+++ b/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html
@@ -415,7 +415,7 @@ window.addEventListener('scroll',changeHeaderBg);
This is only possible when both devices are connected to the same local network. To send and receive messages mobile app has to be connected to the Internet.
⚡️ Quick start - how to use it
On desktop
-If you don't have desktop app installed yet, download it and create any chat profile - you don't need to use it, and when you create it there are no server requests sent and no accounts are created. Think about it as about user profile on your computer.
+If you don't have desktop app installed yet, download it and create any chat profile - you don't need to use it, and when you create it there are no server requests sent and no accounts are created. Think about it as about user profile on your computer.
Then in desktop app settings choose Link a mobile - it will show a QR code.
On mobile
@@ -425,7 +425,7 @@ window.addEventListener('scroll',changeHeaderBg);
If it is an Android app, you can move the app to background, but iOS app has to remain open. In both cases, while you are using mobile profiles from desktop, you won't be able to use mobile app.
The subsequent connections happen much faster - by default, the desktop app broadcasts its session address to the network, in encrypted form, and mobile app connects to it once you choose Use from desktop in mobile app settings.
How does it work?
-The way we designed this solution avoided any security compromises, and the end-to-end encryption remained as secure as it was - it uses double-ratchet algorithm, with perfect forward secrecy, post-compromise security and deniability.
+The way we designed this solution avoided any security compromises, and the end-to-end encryption remained as secure as it was - it uses double-ratchet algorithm, with perfect forward secrecy, post-compromise security and deniability.
This solution is similar to WhatsApp and WeChat. But unlike these apps, no server is involved in the connection between mobile and desktop. The connection itself uses a new SimpleX Remote Control Protocol (XRCP) based on secure TLS 1.3 and additional quantum-resistant encryption inside TLS. You can read XRCP protocol specification and threat model in this document. We will soon be augmenting double ratchet to be resistant to quantum computers as well.
The downside of this approach is that mobile device has to be connected to the same local network as desktop. But the upside is that the connection is secure, and you do not need to have a copy of all your data on desktop, which usually has lower security than mobile.
Please note, that the files you send, save or play from desktop app, and also images you view are automatically saved on your desktop device (encrypted by default except videos). To remove all these files you can unlink the paired mobile device from the desktop app settings – there will be an option soon allowing to remove the files without unlinking the mobile.
@@ -465,8 +465,8 @@ window.addEventListener('scroll',changeHeaderBg);
You can find the full list of fixed bugs and small improvements in the release notes.
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html b/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html
index 99a3660288..1c8afd37dd 100644
--- a/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html
+++ b/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html
@@ -417,7 +417,7 @@ window.addEventListener('scroll',changeHeaderBg);
"Where do I put notes for myself?" was a very common support question. There was a workaround - you could create an empty group, just with yourself, and use it to save notes, but it was not very convenient, and you could accidentally add members there.
This version has a more convenient and private alternative - the Private notes. It looks like an ordinary conversation where you can put text messages, links with previews, and any media and files, but they are not sent anywhere - they are stored locally, only on your device, with encrypted files.
-You can access the Private notes created in mobile app from desktop app too, by linking a mobile and desktop apps - the feature added in the previous version. It allows to conveniently share files between the devices without sending them over the Internet.
+You can access the Private notes created in mobile app from desktop app too, by linking a mobile and desktop apps - the feature added in the previous version. It allows to conveniently share files between the devices without sending them over the Internet.
Group history
In the previous version, when users joined groups, they only saw an empty conversation, and the notifications of being connected to other members. This version allows group admins sending recent group history to the new members - this option is enabled by default for new groups, and can be enabled for the existing groups in the preferences. So now new members can join the conversation as soon as they join.
@@ -434,12 +434,12 @@ window.addEventListener('scroll',changeHeaderBg);
Other improvements in this version:
- you can now reveal secret messages by tapping. To send a secret message wrap in "#" characters, e.g. "#password#".
-- you can delete the last user profile, simplifying account deletion. If you have hidden user profiles, they won't be deleted in this case, and will be accessible again once you create a new profile.
+- you can delete the last user profile, simplifying account deletion. If you have hidden user profiles, they won't be deleted in this case, and will be accessible again once you create a new profile.
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html b/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html
index fb5c9e26db..8fe98bdb0d 100644
--- a/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html
+++ b/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html
@@ -379,6 +379,7 @@ window.addEventListener('scroll',changeHeaderBg);
SimpleX Chat v5.6 beta: adding quantum resistance to Signal double ratchet algorithm
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Published: Mar 14, 2024
This is a major upgrade for SimpleX messaging protocols, we are really proud to present the results of the hard work of our whole team on the Pi day.
This post also covers various aspects of end-to-end encryption, compares different messengers, and explains why and how quantum-resistant encryption is added to SimpleX Chat:
@@ -430,7 +431,7 @@ window.addEventListener('scroll',changeHeaderBg);
The only effective mitigation to these attacks is to pad all messages to a fixed size. Using space-efficient schemes like Padme, or padding to encryption block size is ineffective for mitigating these attacks, as they still allow differentiating message sizes.
To the best of our knowledge, the only messengers other than SimpleX Chat that pad all messages to a fixed packet size are Cwtch and no longer developed Pond - SimpleX design can be seen as an evolution of Pond design.
2. Compromised confidential messages - mitigated by repudiation (deniability)
-Many users are very interested in having ability to irreversibly delete sent messages from the recipients devices. But not only would this ability violate data sovereignty of device owners, it is also completely ineffective, as the recipients could simply put the device offline or use a modified client app to ignore message deletion requests. While SimpleX Chat provides such features as disappearing messages and the ability to irreversibly delete sent messages provided both parties agree to that, these are convenience features, and they cannot be considered security measures.
+Many users are very interested in having ability to irreversibly delete sent messages from the recipients devices. But not only would this ability violate data sovereignty of device owners, it is also completely ineffective, as the recipients could simply put the device offline or use a modified client app to ignore message deletion requests. While SimpleX Chat provides such features as disappearing messages and the ability to irreversibly delete sent messages provided both parties agree to that, these are convenience features, and they cannot be considered security measures.
The solution to that is well known to cryptographers - it is the quality of the encryption algorithms called "repudiation", sometimes also called "deniability". This is the ability of the senders to plausibly deny having sent any messages, because cryptographic algorithms used to encrypt allow recipients forging these messages on their devices, so while the encryption proves authenticity of the message to the recipient, it cannot be used as a proof to any third party.
Putting it all in a simpler language - a sender can claim that the recipient forged messages on their device, and deny ever having sent them. The recipient will not be able to provide any cryptographic proof. This quality makes digital conversation having the same qualities as private off-the-record conversation - that's why the family of algorithms that provide these qualities are called off-the-record (OTR) encryption.
Repudiation is still a rather new concept - the first off-the-record algorithms were proposed in 2004 and were only offered to a wide range of users in Signal messenger. This concept is still quite badly understood by users and society, and yet to have been used as the defense in any public court cases, as legal systems evolve much slower than technology. In high profile cases repudiation can be used as an effective evidence for the defense.
@@ -441,18 +442,18 @@ window.addEventListener('scroll',changeHeaderBg);
4. Compromised long-term or session - mitigated by break-in recovery
This attack is much less understood by the users, and forward secrecy does not protect from it. Arguably, it's almost impossible to compromise individual message keys without compromising long-term or session keys. So the ability of the encryption to recover from break-in (attacker making a copy of the device data without retaining the ongoing access) is both very important and pragmatic - break-in attacks are simpler to execute on mobile devices during short-term device access than long-term ongoing compromise.
Out of all encryption algorithms known to us only Signal double ratchet algorithm (also referred to as Signal algorithm or double ratchet algorithm, which is not the same as Signal messaging platform and protocols) provides the ability for the encryption security to recover after break-ins attacks. This recovery happens automatically and transparently to the users, without them doing anything special or even knowing about break-in, by simply sending messages. Every time one of the communication parties replies to another party message, new random keys are generated and previously stolen keys become useless.
-Double ratchet algorithm is used in Signal, Cwtch and SimpleX Chat. This is why you cannot use SimpleX Chat profile on more than one device at the same time - the encryption scheme rotates the long term keys, randomly, and keys on another device become useless, as they would become useless for the attacker who stole them. Security always has some costs to the convenience.
+Double ratchet algorithm is used in Signal, Cwtch and SimpleX Chat. But Signal app by allowing to use the same profile on multiple devices compromises the break-in recovery function of Signal algorithm, as explained in this paper. Because of break-in recovery you cannot use SimpleX Chat profile on more than one device at the same time - the encryption scheme rotates the long term keys, randomly, and keys on another device become useless, as they would become useless for the attacker who stole them. Security always has some costs to the convenience.
5. Man-in-the-middle attack - mitigated by two-factor key exchange
Many people incorrectly believe that security of end-to-end encryption cannot be broken by communication provider. But end-to-end encryption is only as secure as key exchange. While any intermediary passing the keys between senders and recipients cannot recover the private keys from the public keys, they can simply replace the passed public keys with their own and then proxy all communication between the users having full access to the original messages. So instead of having an end-to-end encrypted channel, users would have two half-way encrypted channels - between users and their communication intermediary.
Pictures below illustrate how this attack works for RSA encryption.
1) Alice sends the key to Bob (e.g. via p2p network or via the messaging server).
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2) Now Bob can send encrypted messages to Alice - he believes they are secure!
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3) But the key could have been intercepted and substituted by Tom (the attacker, or a service provider).
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4) Now the attacker can read the messages without Alice and Bob knowing.
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The attack on Diffie-Hellman (or on quantum-resistant) key exchange, when both parties send their public keys (or public key and ciphertext), requires the attacker to intercept and replace both keys, but the outcome remains the same - if all communication is passed via a single channel, as it is usually the case with communication services, then any attacker that has inside access to the service can selectively compromise some of the conversations. Two years ago I wrote the post about this vulnerability of end-to-end encryption to MITM attacks.
All known mitigations of this attack require using the secondary communication channel to ensure that the keys have not been substituted. The most secure approach is to make user's key (or key fingerprint) a part of the user's address or connection link, thus making two-factor key exchange non-optional. This approach is used in Session, Cwtch and SimpleX Chat.
A less secure approach is to provide users an optional way to compare security codes - this is what is done by Signal, Element and many other messengers. The problem with this post-key-exchange verification is that it is optional, and is usually skipped by the majority of the users. Also, this security code can change because the user changed the device, or as a result of the attack via the service provider. When you see in the client app the notification that the security code changed, it's pointless to ask in the same messenger whether the device was changed, as if it were an attack, the attacker would simply confirm it. Instead, the security code needs to be re-validated again via another channel. A good security practice for the users would be to warn their communication partners about the intention to switch the device in advance, before the security code is changed.
@@ -472,7 +473,7 @@ window.addEventListener('scroll',changeHeaderBg);
How secure is end-to-end encryption in different messengers?
This comparison may be incorrect in some of the columns. We apologize if some of the points are incorrect, please let us know about any mistakes so we can amend them!
The main objective here is to establish the framework for comparing the security of end-to-end encryption schemes, and to highlight any areas for improvement, not to criticize any implementations.
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+
1 Repudiation in SimpleX Chat will include client-server protocol from v5.7 or v5.8. Currently it is implemented but not enabled yet, as its support requires releasing the relay protocol that breaks backward compatibility.
2 Post-quantum cryptography is available in beta version, as opt-in only for direct conversations. See below how it will be rolled-out further.
Some columns are marked with a yellow checkmark:
@@ -517,15 +518,15 @@ window.addEventListener('scroll',changeHeaderBg);
Next for post-quantum crypto - all direct chats, small groups and security audit
We will be making quantum resistance default for all direct chats in v5.7, and we plan that all existing direct chats will be automatically upgraded when both contacts install v5.7.
We will also be adding quantum resistance to small groups up to 10-20 members. Computing cryptographic keys is much slower, in comparison, and it would be very inefficient (and completely unnecessary) for large public groups.
-We have also arranged a 3rd party cryptographic review of our protocol and encryption schemes design for June/July 2024 - it will cover the additions to SimpleX protocols since the previous security audit in November 2022, including XFTP protocol we use for file transfers and quantum resistant Signal double ratchet algorithm we just released in this beta version.
+We have also arranged a 3rd party cryptographic review of our protocol and encryption schemes design for June/July 2024 - it will cover the additions to SimpleX protocols since the previous security audit in November 2022, including XFTP protocol we use for file transfers and quantum resistant Signal double ratchet algorithm we just released in this beta version.
In November 2024 we will be conducting further implementation audit, with double the scope of our 2022 audit.
Security audits are very expensive, as they require employing exceptionally competent engineers and cryptographers, and it does stretch our budgets - so any donations to help us cover the costs would be hugely helpful.
That's it for now!
Thank you for helping us improve the app, and look forward to your feedback.
SimpleX network
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html b/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html
index 28908865e9..f6217d0191 100644
--- a/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html
+++ b/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html
@@ -413,7 +413,7 @@ window.addEventListener('scroll',changeHeaderBg);
What's new in v5.6
Quantum resistant end-to-end encryption (BETA)
Adding post-quantum resistance to the double ratchet end-to-end encryption algorithm in SimpleX Chat is a major upgrade to messaging protocols, and it creates the security against the future quantum computers.
-I wrote in detail in the previous post about various properties of end-to-end encryption and how exactly quantum resistance is implemented in SimpleX Chat - currently SimpleX Chat has the most secure end-to-end encryption design against the present and future attacks.
+I wrote in detail in the previous post about various properties of end-to-end encryption and how exactly quantum resistance is implemented in SimpleX Chat - currently SimpleX Chat has the most secure end-to-end encryption design against the present and future attacks.
We plan to perform a security audit of this design and implementation later this year.
Post-quantum encryption is currently added as opt-in and has to be separately enabled to be active for the new contacts, and, additionally, can be enabled for the existing contacts.
@@ -438,7 +438,7 @@ window.addEventListener('scroll',changeHeaderBg);
Since we added the audio and video calls in 2022 a lot of work was done to improve the stability of calls. One of the usability downsides until this release was that it was impossible to use the app during the call.
This version solved this problem - now you can return back to the app without interrupting the call and use any of the app functions - for example, you can send the messages or files to the person you are in the call with. If this is a video call, you will continue seeing your contact in a small picture-in-picture view.
Migrate all app data to another device via QR code
-We always believed that cross-platform data portability is very important for any software. Users own their data, and they should have a way to export it from any software they use. So from the version of SimpleX Chat released in July 2022 it was possible to export the database as a self-contained file, including all contacts, messages and files, and import it on a new device.
+We always believed that cross-platform data portability is very important for any software. Users own their data, and they should have a way to export it from any software they use. So from the version of SimpleX Chat released in July 2022 it was possible to export the database as a self-contained file, including all contacts, messages and files, and import it on a new device.
"How can I migrate my data to another device?" was one of the most frequent user questions, but until this release this process was quite complex, requiring too many steps, and most non-technical users were not willing to try it, as even though it was reliable, it appeared risky.
This release made the app data migration very simple, see the steps below.
Start the migration on the source device
@@ -464,8 +464,8 @@ window.addEventListener('scroll',changeHeaderBg);
The database cannot be used on two devices at the same time, doing so would make it impossible to decrypt the received messages. This is a security measure - the break-in recovery property of double ratchet algorithm.
SimpleX network
Some links to answer the most common questions:
-How can SimpleX deliver messages without user identifiers.
-What are the risks to have identifiers assigned to the users.
+How can SimpleX deliver messages without user identifiers.
+What are the risks to have identifiers assigned to the users.
Technical details and limitations.
How SimpleX is different from Session, Matrix, Signal, etc..
Please also see our website.
diff --git a/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html b/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html
index 81116ac6d9..5b03310217 100644
--- a/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html
+++ b/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html
@@ -391,7 +391,7 @@ window.addEventListener('scroll',changeHeaderBg);
Some of the world’s top engineers often go to these companies because of the benefits and financial opportunities. We can question their ethics all day long, but we also need to question if the web would look significantly different if there were as many opportunities at privacy-first companies with purpose and strong, proven moral boundaries, set up in a way that can guarantee operational independence from any shareholders and VCs.
SimpleX could have taken the route of other companies in the privacy space, whether it’s Skiff which rushed to take a large amount of VC money only to shutter its doors after an acquisition, leaving its users hanging with many unanswered questions, or giving up control of the company, which would puts its future solely in the hands of VCs with majority ownership. SimpleX aims to prevent this, and in fact has left money on the table to ensure that it does not occur. Had it not been for this information, I would not have joined, and I would have remained a user of the product, albeit a very cautious one, constantly wondering whether it will be sold or corrupted.
It’s worth noting that some private foundations operate on the VC model in supporting nonprofits, either by requiring Board seats or requesting that their funding be used towards very specific objectives not always in alignment with the organization’s values and mission. It’s also worth noting that some nonprofits actually operate on the models of surveillance and censorship. Therefore, whether an organization or company is VC-backed or a nonprofit should not be the sole factor in deciding whether or not it is trustworthy. Actions are important, with full transparency being one of the most critical factors, and being fully open source being another to attract valid criticisms and audits to ensure any product or protocol lives up to its privacy and security promise. SimpleX Chat prides itself on being both transparent and open, on top of also being fully decentralized. If you’re new to it and eager to know more, you can start with this overview.
-Another important consideration is that the SimpleX network does have a plan that would rely on users' payments for specific or tailored services, and not on some other sources of revenue or funds (ads, etc.). Building anything that users would be willing to pay for requires substantially more time and resources, hence the VC route to establish a business model that doesn’t translate to the user being the product. But any business services need to be separate from SimpleX as a public interest technology. As outlined in this recent post, I’ll be using my background in nonprofit governance structures to ensure that the SimpleX network protocols evolve under the stewardship of nonprofit entities in various jurisdictions, so that its continued evolution aligns more closely with the vision of community-driven, independent and decentralized governance. This would help create a necessary balance between different structures, in the same way many tech nonprofits also have for-profit subsidiaries to attract fee-for-service agreements to sustain their operations.
+Another important consideration is that the SimpleX network does have a plan that would rely on users' payments for specific or tailored services, and not on some other sources of revenue or funds (ads, etc.). Building anything that users would be willing to pay for requires substantially more time and resources, hence the VC route to establish a business model that doesn’t translate to the user being the product. But any business services need to be separate from SimpleX as a public interest technology. As outlined in this recent post, I’ll be using my background in nonprofit governance structures to ensure that the SimpleX network protocols evolve under the stewardship of nonprofit entities in various jurisdictions, so that its continued evolution aligns more closely with the vision of community-driven, independent and decentralized governance. This would help create a necessary balance between different structures, in the same way many tech nonprofits also have for-profit subsidiaries to attract fee-for-service agreements to sustain their operations.
In summary: My decision to join Simplex Chat, despite my deep-rooted beliefs and skepticism towards VC funding, reflects a broader realization: that the fight for privacy, security, and decentralization in today’s web is multifaceted and sometimes requires us to depart from our comfort zones to explore sustainable paths for continuous growth and impact so that open source privacy tools and protocols are no longer “niche”, but universally accessible standards. As long as nothing in this journey compromises our moral principles and integrity, this will remain a very worthwhile goal to pursue.
- Personal info (email address, user IDs, phone number)
When stored, aggregated and analyzed, this metadata provides ample information that could potentially incriminate someone or be submitted to authorities. When WhatsApp and Facebook Messenger enabled end-to-end encryption for messages, of course it was a welcome and widely celebrated change. But it’s important to remember that not all end-to-end encryption utilizes the same standards, some implementations are more secure than others, so it’s something that shouldn’t necessarily be accepted at face value. More importantly: collecting and storing an obscene amount of metadata should invite global scrutiny, considering this data is often combined with whatever other information companies like Meta harvest about your identity (which is a lot.)
When stored, aggregated and analyzed, this metadata provides ample information that could potentially incriminate someone or be submitted to authorities. When WhatsApp and Facebook Messenger enabled end-to-end encryption for messages, of course it was a welcome and widely celebrated change. But it’s important to remember that not all end-to-end encryption utilizes the same standards, some implementations are more secure than others, so it’s something that shouldn’t necessarily be accepted at face value. More importantly: collecting and storing an obscene amount of metadata should invite global scrutiny, considering this data is often combined with whatever other information companies like Meta harvest about your identity (which is a lot.)
This is one of the many reasons why we need to resist giving out our phone numbers just to access an app, especially to do something as personal and intimate as private messaging. Even though users can sometimes mask their numbers with a username, their identity on the app is still fundamentally tied to their phone number. App operators have access to this, as well as user contacts. Additionally, with a simple modification to the app's source code, the contacts may also gain access in some cases. This should raise more concerns about privacy, and it makes the need for anonymity difficult to achieve.
Everyone has a different threat model (and if you don’t yet, now is a good time to create one). For many users today, WhatsApp and other apps may be sufficient for their specific needs, especially in connecting with families and friends who are already on the app and unlikely to migrate elsewhere. If that suits your life and needs, and if you’re aware and consciously accept the risks, great.
But we also need to acknowledge that the world is becoming increasingly dangerous in the way AI is being used to supercharge surveillance, and we need to be educated and aware of the risks this is already having on our lives and what it subjects others in your network to when you choose metadata-heavy apps as your primary form of communication. Having alternatives will always be important, even if it’s not what you default to for everyday messaging. Recognize who in your social circles might require the extra privacy, anonymity and security, so that you can play a role in protecting vulnerable individuals who need it most. The messaging app you choose implicates others as well, not just yourself, and while you personally may not require complete privacy, others might have their lives depend on it.
End-to-end encryption is a solid start, but it's just the beginning of our pursuit for true privacy and security. True privacy means that even when legal demands come knocking, there's no useful metadata to hand over. It's not enough to just protect the content of messages; we need consistent innovation in protecting metadata too.
Changing ingrained habits is tough, but your privacy is always worth the fight. Although giants like WhatsApp and Telegram may dominate global messaging for now, increasing concerns about data harvesting and AI-driven surveillance are fueling demand for alternatives. SimpleX Chat aims to be one of those strong alternatives, hence its radical focus on a decentralized framework with no user identifiers (in other words, nothing that uniquely identifies users on the protocol level to their contacts or to the relays) and extra optionality (self-hosting an SMP server or XFTP server, access via Tor, chat profiles with incognito mode, etc.)
Changing ingrained habits is tough, but your privacy is always worth the fight. Although giants like WhatsApp and Telegram may dominate global messaging for now, increasing concerns about data harvesting and AI-driven surveillance are fueling demand for alternatives. SimpleX Chat aims to be one of those strong alternatives, hence its radical focus on a decentralized framework with no user identifiers (in other words, nothing that uniquely identifies users on the protocol level to their contacts or to the relays) and extra optionality (self-hosting an SMP server or XFTP server, access via Tor, chat profiles with incognito mode, etc.)
As of today, most messaging alternatives, including SimpleX, will have some limitations. But with the limited resources we have, we are committed to daily progress towards creating a truly private messenger that anyone can use while maintaining the features that users have come to know and love in messaging interfaces. We want to be the prime example of a messenger that achieves genuine privacy without compromising it for convenience. We need to be able to reliably move away from small and niche use cases to endorsing and enforcing global standards for privacy and making it accessible for all users regardless of their technical expertise.
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