diff --git a/cmd/ingestor/coverage_boost_test.go b/cmd/ingestor/coverage_boost_test.go
index fa7315c0..d1a59b72 100644
--- a/cmd/ingestor/coverage_boost_test.go
+++ b/cmd/ingestor/coverage_boost_test.go
@@ -461,7 +461,7 @@ func TestDecodeAdvertLocationTruncated(t *testing.T) {
 	buf[100] = 0x11
 	// Only 4 bytes after flags — not enough for full location (needs 8)
 
-	p := decodeAdvert(buf[:105])
+	p := decodeAdvert(buf[:105], false)
 	if p.Error != "" {
 		t.Fatalf("error: %s", p.Error)
 	}
@@ -483,7 +483,7 @@ func TestDecodeAdvertFeat1Truncated(t *testing.T) {
 	buf[100] = 0x21
 	// Only 1 byte after flags — not enough for feat1 (needs 2)
 
-	p := decodeAdvert(buf[:102])
+	p := decodeAdvert(buf[:102], false)
 	if p.Feat1 != nil {
 		t.Error("feat1 should be nil with truncated data")
 	}
@@ -504,7 +504,7 @@ func TestDecodeAdvertFeat2Truncated(t *testing.T) {
 	buf[102] = 0x00
 	// Only 1 byte left — not enough for feat2
 
-	p := decodeAdvert(buf[:104])
+	p := decodeAdvert(buf[:104], false)
 	if p.Feat1 == nil {
 		t.Error("feat1 should be set")
 	}
@@ -544,7 +544,7 @@ func TestDecodeAdvertSensorBadTelemetry(t *testing.T) {
 	buf[105] = 0x20
 	buf[106] = 0x4E
 
-	p := decodeAdvert(buf[:107])
+	p := decodeAdvert(buf[:107], false)
 	if p.BatteryMv != nil {
 		t.Error("battery_mv=0 should be nil")
 	}
@@ -740,7 +740,7 @@ func TestDecodeAdvertSensorNoName(t *testing.T) {
 	buf[103] = 0xC4
 	buf[104] = 0x09
 
-	p := decodeAdvert(buf[:105])
+	p := decodeAdvert(buf[:105], false)
 	if p.Error != "" {
 		t.Fatalf("error: %s", p.Error)
 	}
@@ -835,7 +835,7 @@ func TestDecodePacketNoPathByteAfterHeader(t *testing.T) {
 	// Non-transport route, but only header byte (no path byte)
 	// Actually 0A alone = 1 byte, but we need >= 2
 	// Header + exactly at offset boundary
-	_, err := DecodePacket("0A", nil)
+	_, err := DecodePacket("0A", nil, false)
 	if err == nil {
 		t.Error("should error - too short")
 	}
@@ -856,7 +856,7 @@ func TestDecodeAdvertNameNoNull(t *testing.T) {
 	// Name without null terminator — goes to end of buffer
 	copy(buf[101:], []byte("LongNameNoNull"))
 
-	p := decodeAdvert(buf[:115])
+	p := decodeAdvert(buf[:115], false)
 	if p.Name != "LongNameNoNull" {
 		t.Errorf("name=%q, want LongNameNoNull", p.Name)
 	}
diff --git a/cmd/ingestor/db_test.go b/cmd/ingestor/db_test.go
index b9ef3f6d..c265cd59 100644
--- a/cmd/ingestor/db_test.go
+++ b/cmd/ingestor/db_test.go
@@ -576,7 +576,7 @@ func TestEndToEndIngest(t *testing.T) {
 	// Simulate full pipeline: decode + insert
 	rawHex := "120046D62DE27D4C5194D7821FC5A34A45565DCC2537B300B9AB6275255CEFB65D840CE5C169C94C9AED39E8BCB6CB6EB0335497A198B33A1A610CD3B03D8DCFC160900E5244280323EE0B44CACAB8F02B5B38B91CFA18BD067B0B5E63E94CFC85F758A8530B9240933402E0E6B8F84D5252322D52"
 
-	decoded, err := DecodePacket(rawHex, nil)
+	decoded, err := DecodePacket(rawHex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -764,7 +764,7 @@ func TestInsertTransmissionNilSNRRSSI(t *testing.T) {
 
 func TestBuildPacketData(t *testing.T) {
 	rawHex := "0A00D69FD7A5A7475DB07337749AE61FA53A4788E976"
-	decoded, err := DecodePacket(rawHex, nil)
+	decoded, err := DecodePacket(rawHex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -818,7 +818,7 @@ func TestBuildPacketData(t *testing.T) {
 func TestBuildPacketDataWithHops(t *testing.T) {
 	// A packet with actual hops in the path
 	raw := "0505AABBCCDDEE" + strings.Repeat("00", 10)
-	decoded, err := DecodePacket(raw, nil)
+	decoded, err := DecodePacket(raw, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -834,7 +834,7 @@ func TestBuildPacketDataWithHops(t *testing.T) {
 }
 
 func TestBuildPacketDataNilSNRRSSI(t *testing.T) {
-	decoded, _ := DecodePacket("0A00"+strings.Repeat("00", 10), nil)
+	decoded, _ := DecodePacket("0A00"+strings.Repeat("00", 10), nil, false)
 	msg := &MQTTPacketMessage{Raw: "0A00" + strings.Repeat("00", 10)}
 	pkt := BuildPacketData(msg, decoded, "", "")
 
@@ -1624,7 +1624,7 @@ func TestObsTimestampIndexMigration(t *testing.T) {
 
 func TestBuildPacketDataScoreAndDirection(t *testing.T) {
 	rawHex := "0A00D69FD7A5A7475DB07337749AE61FA53A4788E976"
-	decoded, err := DecodePacket(rawHex, nil)
+	decoded, err := DecodePacket(rawHex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1647,7 +1647,7 @@ func TestBuildPacketDataScoreAndDirection(t *testing.T) {
 }
 
 func TestBuildPacketDataNilScoreDirection(t *testing.T) {
-	decoded, _ := DecodePacket("0A00"+strings.Repeat("00", 10), nil)
+	decoded, _ := DecodePacket("0A00"+strings.Repeat("00", 10), nil, false)
 	msg := &MQTTPacketMessage{Raw: "0A00" + strings.Repeat("00", 10)}
 	pkt := BuildPacketData(msg, decoded, "", "")
 
diff --git a/cmd/ingestor/decoder.go b/cmd/ingestor/decoder.go
index 9d29746b..c5a4ddff 100644
--- a/cmd/ingestor/decoder.go
+++ b/cmd/ingestor/decoder.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"crypto/aes"
+	"crypto/ed25519"
 	"crypto/hmac"
 	"crypto/sha256"
 	"encoding/binary"
@@ -109,6 +110,7 @@ type Payload struct {
 	Timestamp     uint32       `json:"timestamp,omitempty"`
 	TimestampISO  string       `json:"timestampISO,omitempty"`
 	Signature     string       `json:"signature,omitempty"`
+	SignatureValid *bool       `json:"signatureValid,omitempty"`
 	Flags         *AdvertFlags `json:"flags,omitempty"`
 	Lat           *float64     `json:"lat,omitempty"`
 	Lon           *float64     `json:"lon,omitempty"`
@@ -215,7 +217,27 @@ func decodeAck(buf []byte) Payload {
 	}
 }
 
-func decodeAdvert(buf []byte) Payload {
+func validateAdvertSignature(pubKeyHex, signatureHex string, timestamp uint32, appdata []byte) (bool, error) {
+	pubKey, err := hex.DecodeString(pubKeyHex)
+	if err != nil || len(pubKey) != 32 {
+		return false, fmt.Errorf("invalid pubkey")
+	}
+
+	signature, err := hex.DecodeString(signatureHex)
+	if err != nil || len(signature) != 64 {
+		return false, fmt.Errorf("invalid signature")
+	}
+
+	// Signed data: pubKey (32) + timestamp (4 LE) + appdata
+	message := make([]byte, 32+4+len(appdata))
+	copy(message[0:32], pubKey)
+	binary.LittleEndian.PutUint32(message[32:36], timestamp)
+	copy(message[36:], appdata)
+
+	return ed25519.Verify(ed25519.PublicKey(pubKey), message, signature), nil
+}
+
+func decodeAdvert(buf []byte, validateSignatures bool) Payload {
 	if len(buf) < 100 {
 		return Payload{Type: "ADVERT", Error: "too short for advert", RawHex: hex.EncodeToString(buf)}
 	}
@@ -233,6 +255,15 @@ func decodeAdvert(buf []byte) Payload {
 		Signature:    signature,
 	}
 
+	if validateSignatures {
+		valid, err := validateAdvertSignature(pubKey, signature, timestamp, appdata)
+		if err != nil {
+			p.SignatureValid = &[]bool{false}[0] // false
+		} else {
+			p.SignatureValid = &valid
+		}
+	}
+
 	if len(appdata) > 0 {
 		flags := appdata[0]
 		advType := int(flags & 0x0F)
@@ -506,7 +537,7 @@ func decodeTrace(buf []byte) Payload {
 	return p
 }
 
-func decodePayload(payloadType int, buf []byte, channelKeys map[string]string) Payload {
+func decodePayload(payloadType int, buf []byte, channelKeys map[string]string, validateSignatures bool) Payload {
 	switch payloadType {
 	case PayloadREQ:
 		return decodeEncryptedPayload("REQ", buf)
@@ -517,7 +548,7 @@ func decodePayload(payloadType int, buf []byte, channelKeys map[string]string) P
 	case PayloadACK:
 		return decodeAck(buf)
 	case PayloadADVERT:
-		return decodeAdvert(buf)
+		return decodeAdvert(buf, validateSignatures)
 	case PayloadGRP_TXT:
 		return decodeGrpTxt(buf, channelKeys)
 	case PayloadANON_REQ:
@@ -532,7 +563,7 @@ func decodePayload(payloadType int, buf []byte, channelKeys map[string]string) P
 }
 
 // DecodePacket decodes a hex-encoded MeshCore packet.
-func DecodePacket(hexString string, channelKeys map[string]string) (*DecodedPacket, error) {
+func DecodePacket(hexString string, channelKeys map[string]string, validateSignatures bool) (*DecodedPacket, error) {
 	hexString = strings.ReplaceAll(hexString, " ", "")
 	hexString = strings.ReplaceAll(hexString, "\n", "")
 	hexString = strings.ReplaceAll(hexString, "\r", "")
@@ -570,7 +601,7 @@ func DecodePacket(hexString string, channelKeys map[string]string) (*DecodedPack
 	offset += bytesConsumed
 
 	payloadBuf := buf[offset:]
-	payload := decodePayload(header.PayloadType, payloadBuf, channelKeys)
+	payload := decodePayload(header.PayloadType, payloadBuf, channelKeys, validateSignatures)
 
 	// TRACE packets store hop IDs in the payload (buf[9:]) rather than the header
 	// path field. The header path byte still encodes hashSize in bits 6-7, which
diff --git a/cmd/ingestor/decoder_test.go b/cmd/ingestor/decoder_test.go
index 22697525..eafe7c9b 100644
--- a/cmd/ingestor/decoder_test.go
+++ b/cmd/ingestor/decoder_test.go
@@ -55,7 +55,7 @@ func TestDecodeHeaderPayloadTypes(t *testing.T) {
 
 func TestDecodePathZeroHops(t *testing.T) {
 	// 0x00: 0 hops, 1-byte hashes
-	pkt, err := DecodePacket("0500"+strings.Repeat("00", 10), nil)
+	pkt, err := DecodePacket("0500"+strings.Repeat("00", 10), nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -72,7 +72,7 @@ func TestDecodePathZeroHops(t *testing.T) {
 
 func TestDecodePath1ByteHashes(t *testing.T) {
 	// 0x05: 5 hops, 1-byte hashes → 5 path bytes
-	pkt, err := DecodePacket("0505"+"AABBCCDDEE"+strings.Repeat("00", 10), nil)
+	pkt, err := DecodePacket("0505"+"AABBCCDDEE"+strings.Repeat("00", 10), nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -95,7 +95,7 @@ func TestDecodePath1ByteHashes(t *testing.T) {
 
 func TestDecodePath2ByteHashes(t *testing.T) {
 	// 0x45: 5 hops, 2-byte hashes
-	pkt, err := DecodePacket("0545"+"AA11BB22CC33DD44EE55"+strings.Repeat("00", 10), nil)
+	pkt, err := DecodePacket("0545"+"AA11BB22CC33DD44EE55"+strings.Repeat("00", 10), nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -112,7 +112,7 @@ func TestDecodePath2ByteHashes(t *testing.T) {
 
 func TestDecodePath3ByteHashes(t *testing.T) {
 	// 0x8A: 10 hops, 3-byte hashes
-	pkt, err := DecodePacket("058A"+strings.Repeat("AA11FF", 10)+strings.Repeat("00", 10), nil)
+	pkt, err := DecodePacket("058A"+strings.Repeat("AA11FF", 10)+strings.Repeat("00", 10), nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -131,7 +131,7 @@ func TestTransportCodes(t *testing.T) {
 	// Route type 0 (TRANSPORT_FLOOD) should have transport codes
 	// Firmware order: header + transport_codes(4) + path_len + path + payload
 	hex := "14" + "AABB" + "CCDD" + "00" + strings.Repeat("00", 10)
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -149,7 +149,7 @@ func TestTransportCodes(t *testing.T) {
 	}
 
 	// Route type 1 (FLOOD) should NOT have transport codes
-	pkt2, err := DecodePacket("0500"+strings.Repeat("00", 10), nil)
+	pkt2, err := DecodePacket("0500"+strings.Repeat("00", 10), nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -169,7 +169,7 @@ func TestDecodeAdvertFull(t *testing.T) {
 	name := "546573744E6F6465" // "TestNode"
 
 	hex := "1200" + pubkey + timestamp + signature + flags + lat + lon + name
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -227,7 +227,7 @@ func TestDecodeAdvertTypeEnums(t *testing.T) {
 	makeAdvert := func(flagsByte byte) *DecodedPacket {
 		hex := "1200" + strings.Repeat("AA", 32) + "00000000" + strings.Repeat("BB", 64) +
 			strings.ToUpper(string([]byte{hexDigit(flagsByte>>4), hexDigit(flagsByte & 0x0f)}))
-		pkt, err := DecodePacket(hex, nil)
+		pkt, err := DecodePacket(hex, nil, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -272,7 +272,7 @@ func hexDigit(v byte) byte {
 
 func TestDecodeAdvertNoLocationNoName(t *testing.T) {
 	hex := "1200" + strings.Repeat("CC", 32) + "00000000" + strings.Repeat("DD", 64) + "02"
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -291,7 +291,7 @@ func TestDecodeAdvertNoLocationNoName(t *testing.T) {
 }
 
 func TestGoldenFixtureTxtMsg(t *testing.T) {
-	pkt, err := DecodePacket("0A00D69FD7A5A7475DB07337749AE61FA53A4788E976", nil)
+	pkt, err := DecodePacket("0A00D69FD7A5A7475DB07337749AE61FA53A4788E976", nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -314,7 +314,7 @@ func TestGoldenFixtureTxtMsg(t *testing.T) {
 
 func TestGoldenFixtureAdvert(t *testing.T) {
 	rawHex := "120046D62DE27D4C5194D7821FC5A34A45565DCC2537B300B9AB6275255CEFB65D840CE5C169C94C9AED39E8BCB6CB6EB0335497A198B33A1A610CD3B03D8DCFC160900E5244280323EE0B44CACAB8F02B5B38B91CFA18BD067B0B5E63E94CFC85F758A8530B9240933402E0E6B8F84D5252322D52"
-	pkt, err := DecodePacket(rawHex, nil)
+	pkt, err := DecodePacket(rawHex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -337,7 +337,7 @@ func TestGoldenFixtureAdvert(t *testing.T) {
 
 func TestGoldenFixtureUnicodeAdvert(t *testing.T) {
 	rawHex := "120073CFF971E1CB5754A742C152B2D2E0EB108A19B246D663ED8898A72C4A5AD86EA6768E66694B025EDF6939D5C44CFF719C5D5520E5F06B20680A83AD9C2C61C3227BBB977A85EE462F3553445FECF8EDD05C234ECE217272E503F14D6DF2B1B9B133890C923CDF3002F8FDC1F85045414BF09F8CB3"
-	pkt, err := DecodePacket(rawHex, nil)
+	pkt, err := DecodePacket(rawHex, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -354,14 +354,14 @@ func TestGoldenFixtureUnicodeAdvert(t *testing.T) {
 }
 
 func TestDecodePacketTooShort(t *testing.T) {
-	_, err := DecodePacket("FF", nil)
+	_, err := DecodePacket("FF", nil, false)
 	if err == nil {
 		t.Error("expected error for 1-byte packet")
 	}
 }
 
 func TestDecodePacketInvalidHex(t *testing.T) {
-	_, err := DecodePacket("ZZZZ", nil)
+	_, err := DecodePacket("ZZZZ", nil, false)
 	if err == nil {
 		t.Error("expected error for invalid hex")
 	}
@@ -568,7 +568,7 @@ func TestDecodeTracePathParsing(t *testing.T) {
 	// Packet from issue #276: 260001807dca00000000007d547d
 	// Path byte 0x00 → hashSize=1, hops in payload at buf[9:] = 7d 54 7d
 	// Expected path: ["7D", "54", "7D"]
-	pkt, err := DecodePacket("260001807dca00000000007d547d", nil)
+	pkt, err := DecodePacket("260001807dca00000000007d547d", nil, false)
 	if err != nil {
 		t.Fatalf("DecodePacket error: %v", err)
 	}
@@ -590,7 +590,7 @@ func TestDecodeTracePathParsing(t *testing.T) {
 }
 
 func TestDecodeAdvertShort(t *testing.T) {
-	p := decodeAdvert(make([]byte, 50))
+	p := decodeAdvert(make([]byte, 50), false)
 	if p.Error != "too short for advert" {
 		t.Errorf("expected 'too short for advert' error, got %q", p.Error)
 	}
@@ -628,7 +628,7 @@ func TestDecodeEncryptedPayloadValid(t *testing.T) {
 
 func TestDecodePayloadGRPData(t *testing.T) {
 	buf := []byte{0x01, 0x02, 0x03}
-	p := decodePayload(PayloadGRP_DATA, buf, nil)
+	p := decodePayload(PayloadGRP_DATA, buf, nil, false)
 	if p.Type != "UNKNOWN" {
 		t.Errorf("type=%s, want UNKNOWN", p.Type)
 	}
@@ -639,7 +639,7 @@ func TestDecodePayloadGRPData(t *testing.T) {
 
 func TestDecodePayloadRAWCustom(t *testing.T) {
 	buf := []byte{0xFF, 0xFE}
-	p := decodePayload(PayloadRAW_CUSTOM, buf, nil)
+	p := decodePayload(PayloadRAW_CUSTOM, buf, nil, false)
 	if p.Type != "UNKNOWN" {
 		t.Errorf("type=%s, want UNKNOWN", p.Type)
 	}
@@ -647,49 +647,49 @@ func TestDecodePayloadRAWCustom(t *testing.T) {
 
 func TestDecodePayloadAllTypes(t *testing.T) {
 	// REQ
-	p := decodePayload(PayloadREQ, make([]byte, 10), nil)
+	p := decodePayload(PayloadREQ, make([]byte, 10), nil, false)
 	if p.Type != "REQ" {
 		t.Errorf("REQ: type=%s", p.Type)
 	}
 
 	// RESPONSE
-	p = decodePayload(PayloadRESPONSE, make([]byte, 10), nil)
+	p = decodePayload(PayloadRESPONSE, make([]byte, 10), nil, false)
 	if p.Type != "RESPONSE" {
 		t.Errorf("RESPONSE: type=%s", p.Type)
 	}
 
 	// TXT_MSG
-	p = decodePayload(PayloadTXT_MSG, make([]byte, 10), nil)
+	p = decodePayload(PayloadTXT_MSG, make([]byte, 10), nil, false)
 	if p.Type != "TXT_MSG" {
 		t.Errorf("TXT_MSG: type=%s", p.Type)
 	}
 
 	// ACK
-	p = decodePayload(PayloadACK, make([]byte, 10), nil)
+	p = decodePayload(PayloadACK, make([]byte, 10), nil, false)
 	if p.Type != "ACK" {
 		t.Errorf("ACK: type=%s", p.Type)
 	}
 
 	// GRP_TXT
-	p = decodePayload(PayloadGRP_TXT, make([]byte, 10), nil)
+	p = decodePayload(PayloadGRP_TXT, make([]byte, 10), nil, false)
 	if p.Type != "GRP_TXT" {
 		t.Errorf("GRP_TXT: type=%s", p.Type)
 	}
 
 	// ANON_REQ
-	p = decodePayload(PayloadANON_REQ, make([]byte, 40), nil)
+	p = decodePayload(PayloadANON_REQ, make([]byte, 40), nil, false)
 	if p.Type != "ANON_REQ" {
 		t.Errorf("ANON_REQ: type=%s", p.Type)
 	}
 
 	// PATH
-	p = decodePayload(PayloadPATH, make([]byte, 10), nil)
+	p = decodePayload(PayloadPATH, make([]byte, 10), nil, false)
 	if p.Type != "PATH" {
 		t.Errorf("PATH: type=%s", p.Type)
 	}
 
 	// TRACE
-	p = decodePayload(PayloadTRACE, make([]byte, 20), nil)
+	p = decodePayload(PayloadTRACE, make([]byte, 20), nil, false)
 	if p.Type != "TRACE" {
 		t.Errorf("TRACE: type=%s", p.Type)
 	}
@@ -925,7 +925,7 @@ func TestComputeContentHashLongFallback(t *testing.T) {
 
 func TestDecodePacketWithWhitespace(t *testing.T) {
 	raw := "0A 00 D6 9F D7 A5 A7 47 5D B0 73 37 74 9A E6 1F A5 3A 47 88 E9 76"
-	pkt, err := DecodePacket(raw, nil)
+	pkt, err := DecodePacket(raw, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -936,7 +936,7 @@ func TestDecodePacketWithWhitespace(t *testing.T) {
 
 func TestDecodePacketWithNewlines(t *testing.T) {
 	raw := "0A00\nD69F\r\nD7A5A7475DB07337749AE61FA53A4788E976"
-	pkt, err := DecodePacket(raw, nil)
+	pkt, err := DecodePacket(raw, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -947,7 +947,7 @@ func TestDecodePacketWithNewlines(t *testing.T) {
 
 func TestDecodePacketTransportRouteTooShort(t *testing.T) {
 	// TRANSPORT_FLOOD (route=0) but only 2 bytes total → too short for transport codes
-	_, err := DecodePacket("1400", nil)
+	_, err := DecodePacket("1400", nil, false)
 	if err == nil {
 		t.Error("expected error for transport route with too-short buffer")
 	}
@@ -1007,7 +1007,7 @@ func TestDecodeHeaderUnknownTypes(t *testing.T) {
 
 func TestDecodePayloadMultipart(t *testing.T) {
 	// MULTIPART (0x0A) falls through to default → UNKNOWN
-	p := decodePayload(PayloadMULTIPART, []byte{0x01, 0x02}, nil)
+	p := decodePayload(PayloadMULTIPART, []byte{0x01, 0x02}, nil, false)
 	if p.Type != "UNKNOWN" {
 		t.Errorf("MULTIPART type=%s, want UNKNOWN", p.Type)
 	}
@@ -1015,7 +1015,7 @@ func TestDecodePayloadMultipart(t *testing.T) {
 
 func TestDecodePayloadControl(t *testing.T) {
 	// CONTROL (0x0B) falls through to default → UNKNOWN
-	p := decodePayload(PayloadCONTROL, []byte{0x01, 0x02}, nil)
+	p := decodePayload(PayloadCONTROL, []byte{0x01, 0x02}, nil, false)
 	if p.Type != "UNKNOWN" {
 		t.Errorf("CONTROL type=%s, want UNKNOWN", p.Type)
 	}
@@ -1039,7 +1039,7 @@ func TestDecodePathTruncatedBuffer(t *testing.T) {
 func TestDecodeFloodAdvert5Hops(t *testing.T) {
 	// From test-decoder.js Test 1
 	raw := "11451000D818206D3AAC152C8A91F89957E6D30CA51F36E28790228971C473B755F244F718754CF5EE4A2FD58D944466E42CDED140C66D0CC590183E32BAF40F112BE8F3F2BDF6012B4B2793C52F1D36F69EE054D9A05593286F78453E56C0EC4A3EB95DDA2A7543FCCC00B939CACC009278603902FC12BCF84B706120526F6F6620536F6C6172"
-	pkt, err := DecodePacket(raw, nil)
+	pkt, err := DecodePacket(raw, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1410,7 +1410,7 @@ func TestDecodeAdvertWithTelemetry(t *testing.T) {
 		name + nullTerm +
 		hex.EncodeToString(batteryLE) + hex.EncodeToString(tempLE)
 
-	pkt, err := DecodePacket(hexStr, nil)
+	pkt, err := DecodePacket(hexStr, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1449,7 +1449,7 @@ func TestDecodeAdvertWithTelemetryNegativeTemp(t *testing.T) {
 		name + nullTerm +
 		hex.EncodeToString(batteryLE) + hex.EncodeToString(tempLE)
 
-	pkt, err := DecodePacket(hexStr, nil)
+	pkt, err := DecodePacket(hexStr, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1476,7 +1476,7 @@ func TestDecodeAdvertWithoutTelemetry(t *testing.T) {
 	name := hex.EncodeToString([]byte("Node1"))
 
 	hexStr := "1200" + pubkey + timestamp + signature + flags + name
-	pkt, err := DecodePacket(hexStr, nil)
+	pkt, err := DecodePacket(hexStr, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1503,7 +1503,7 @@ func TestDecodeAdvertNonSensorIgnoresTelemetryBytes(t *testing.T) {
 	extraBytes := "B40ED403" // battery-like and temp-like bytes
 
 	hexStr := "1200" + pubkey + timestamp + signature + flags + name + nullTerm + extraBytes
-	pkt, err := DecodePacket(hexStr, nil)
+	pkt, err := DecodePacket(hexStr, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1531,7 +1531,7 @@ func TestDecodeAdvertTelemetryZeroTemp(t *testing.T) {
 		name + nullTerm +
 		hex.EncodeToString(batteryLE) + hex.EncodeToString(tempLE)
 
-	pkt, err := DecodePacket(hexStr, nil)
+	pkt, err := DecodePacket(hexStr, nil, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1555,7 +1555,7 @@ func TestZeroHopDirectHashSize(t *testing.T) {
 	// DIRECT (RouteType=2) + REQ (PayloadType=0) → header byte = 0x02
 	// pathByte=0x00 → hash_count=0, hash_size bits=0 → should get HashSize=0
 	hex := "02" + "00" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -1568,7 +1568,7 @@ func TestZeroHopDirectHashSizeWithNonZeroUpperBits(t *testing.T) {
 	// DIRECT (RouteType=2) + REQ (PayloadType=0) → header byte = 0x02
 	// pathByte=0x40 → hash_count=0, hash_size bits=01 → should still get HashSize=0
 	hex := "02" + "40" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -1581,7 +1581,7 @@ func TestNonDirectZeroPathByteKeepsHashSize(t *testing.T) {
 	// FLOOD (RouteType=1) + REQ (PayloadType=0) → header byte = 0x01
 	// pathByte=0x00 → non-DIRECT should keep HashSize=1
 	hex := "01" + "00" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -1594,7 +1594,7 @@ func TestDirectNonZeroHopKeepsHashSize(t *testing.T) {
 	// DIRECT (RouteType=2) + REQ (PayloadType=0) → header byte = 0x02
 	// pathByte=0x01 → hash_count=1, hash_size=1 → should keep HashSize=1
 	hex := "02" + "01" + repeatHex("BB", 21)
-	pkt, err := DecodePacket(hex, nil)
+	pkt, err := DecodePacket(hex, nil, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
diff --git a/cmd/ingestor/main.go b/cmd/ingestor/main.go
index 0beb3ec2..b930557e 100644
--- a/cmd/ingestor/main.go
+++ b/cmd/ingestor/main.go
@@ -248,7 +248,7 @@ func handleMessage(store *Store, tag string, source MQTTSource, m mqtt.Message,
 	// Format 1: Raw packet (meshcoretomqtt / Cisien format)
 	rawHex, _ := msg["raw"].(string)
 	if rawHex != "" {
-		decoded, err := DecodePacket(rawHex, channelKeys)
+		decoded, err := DecodePacket(rawHex, channelKeys, false)
 		if err != nil {
 			log.Printf("MQTT [%s] decode error: %v", tag, err)
 			return
diff --git a/cmd/server/decoder.go b/cmd/server/decoder.go
index 3c3f8106..0d0bc0fb 100644
--- a/cmd/server/decoder.go
+++ b/cmd/server/decoder.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"crypto/ed25519"
 	"crypto/sha256"
 	"encoding/binary"
 	"encoding/hex"
@@ -92,6 +93,7 @@ type Payload struct {
 	Timestamp       uint32       `json:"timestamp,omitempty"`
 	TimestampISO    string       `json:"timestampISO,omitempty"`
 	Signature       string       `json:"signature,omitempty"`
+	SignatureValid  *bool        `json:"signatureValid,omitempty"`
 	Flags           *AdvertFlags `json:"flags,omitempty"`
 	Lat             *float64     `json:"lat,omitempty"`
 	Lon             *float64     `json:"lon,omitempty"`
@@ -188,7 +190,27 @@ func decodeAck(buf []byte) Payload {
 	}
 }
 
-func decodeAdvert(buf []byte) Payload {
+func validateAdvertSignature(pubKeyHex, signatureHex string, timestamp uint32, appdata []byte) (bool, error) {
+	pubKey, err := hex.DecodeString(pubKeyHex)
+	if err != nil || len(pubKey) != 32 {
+		return false, fmt.Errorf("invalid pubkey")
+	}
+
+	signature, err := hex.DecodeString(signatureHex)
+	if err != nil || len(signature) != 64 {
+		return false, fmt.Errorf("invalid signature")
+	}
+
+	// Signed data: pubKey (32) + timestamp (4 LE) + appdata
+	message := make([]byte, 32+4+len(appdata))
+	copy(message[0:32], pubKey)
+	binary.LittleEndian.PutUint32(message[32:36], timestamp)
+	copy(message[36:], appdata)
+
+	return ed25519.Verify(ed25519.PublicKey(pubKey), message, signature), nil
+}
+
+func decodeAdvert(buf []byte, validateSignatures bool) Payload {
 	if len(buf) < 100 {
 		return Payload{Type: "ADVERT", Error: "too short for advert", RawHex: hex.EncodeToString(buf)}
 	}
@@ -206,6 +228,15 @@ func decodeAdvert(buf []byte) Payload {
 		Signature:    signature,
 	}
 
+	if validateSignatures {
+		valid, err := validateAdvertSignature(pubKey, signature, timestamp, appdata)
+		if err != nil {
+			p.SignatureValid = &[]bool{false}[0] // false
+		} else {
+			p.SignatureValid = &valid
+		}
+	}
+
 	if len(appdata) > 0 {
 		flags := appdata[0]
 		advType := int(flags & 0x0F)
@@ -308,7 +339,7 @@ func decodeTrace(buf []byte) Payload {
 	return p
 }
 
-func decodePayload(payloadType int, buf []byte) Payload {
+func decodePayload(payloadType int, buf []byte, validateSignatures bool) Payload {
 	switch payloadType {
 	case PayloadREQ:
 		return decodeEncryptedPayload("REQ", buf)
@@ -319,7 +350,7 @@ func decodePayload(payloadType int, buf []byte) Payload {
 	case PayloadACK:
 		return decodeAck(buf)
 	case PayloadADVERT:
-		return decodeAdvert(buf)
+		return decodeAdvert(buf, validateSignatures)
 	case PayloadGRP_TXT:
 		return decodeGrpTxt(buf)
 	case PayloadANON_REQ:
@@ -334,7 +365,7 @@ func decodePayload(payloadType int, buf []byte) Payload {
 }
 
 // DecodePacket decodes a hex-encoded MeshCore packet.
-func DecodePacket(hexString string) (*DecodedPacket, error) {
+func DecodePacket(hexString string, validateSignatures bool) (*DecodedPacket, error) {
 	hexString = strings.ReplaceAll(hexString, " ", "")
 	hexString = strings.ReplaceAll(hexString, "\n", "")
 	hexString = strings.ReplaceAll(hexString, "\r", "")
@@ -372,7 +403,7 @@ func DecodePacket(hexString string) (*DecodedPacket, error) {
 	offset += bytesConsumed
 
 	payloadBuf := buf[offset:]
-	payload := decodePayload(header.PayloadType, payloadBuf)
+	payload := decodePayload(header.PayloadType, payloadBuf, validateSignatures)
 
 	// TRACE packets store hop IDs in the payload (buf[9:]) rather than the header
 	// path field. The header path byte still encodes hashSize in bits 6-7, which
diff --git a/cmd/server/decoder_test.go b/cmd/server/decoder_test.go
index 67b6b999..44b6c73a 100644
--- a/cmd/server/decoder_test.go
+++ b/cmd/server/decoder_test.go
@@ -65,7 +65,7 @@ func TestDecodePacket_TransportFloodHasCodes(t *testing.T) {
 	// Path byte: 0x00 (hashSize=1, hashCount=0)
 	// Payload: at least some bytes for GRP_TXT
 	hex := "14AABBCCDD00112233445566778899"
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -85,7 +85,7 @@ func TestDecodePacket_FloodHasNoCodes(t *testing.T) {
 	// Path byte: 0x00 (no hops)
 	// Some payload bytes
 	hex := "110011223344556677889900AABBCCDD"
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -240,7 +240,7 @@ func TestZeroHopDirectHashSize(t *testing.T) {
 	// pathByte=0x00 → hash_count=0, hash_size bits=0 → should get HashSize=0
 	// Need at least a few payload bytes after pathByte.
 	hex := "02" + "00" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -254,7 +254,7 @@ func TestZeroHopDirectHashSizeWithNonZeroUpperBits(t *testing.T) {
 	// pathByte=0x40 → hash_count=0, hash_size bits=01 → should still get HashSize=0
 	// because hash_count is zero (lower 6 bits are 0).
 	hex := "02" + "40" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -267,7 +267,7 @@ func TestZeroHopTransportDirectHashSize(t *testing.T) {
 	// TRANSPORT_DIRECT (RouteType=3) + REQ (PayloadType=0) → header byte = 0x03
 	// 4 bytes transport codes + pathByte=0x00 → hash_count=0 → should get HashSize=0
 	hex := "03" + "11223344" + "00" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -280,7 +280,7 @@ func TestZeroHopTransportDirectHashSizeWithNonZeroUpperBits(t *testing.T) {
 	// TRANSPORT_DIRECT (RouteType=3) + REQ (PayloadType=0) → header byte = 0x03
 	// 4 bytes transport codes + pathByte=0xC0 → hash_count=0, hash_size bits=11 → should still get HashSize=0
 	hex := "03" + "11223344" + "C0" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -293,7 +293,7 @@ func TestNonDirectZeroPathByteKeepsHashSize(t *testing.T) {
 	// FLOOD (RouteType=1) + REQ (PayloadType=0) → header byte = 0x01
 	// pathByte=0x00 → even though hash_count=0, non-DIRECT should keep HashSize=1
 	hex := "01" + "00" + repeatHex("AA", 20)
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -307,7 +307,7 @@ func TestDirectNonZeroHopKeepsHashSize(t *testing.T) {
 	// pathByte=0x01 → hash_count=1, hash_size=1 → should keep HashSize=1
 	// Need 1 hop hash byte after pathByte.
 	hex := "02" + "01" + repeatHex("BB", 21)
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket failed: %v", err)
 	}
@@ -336,7 +336,7 @@ func TestDecodePacket_TraceHopsCompleted(t *testing.T) {
 		"00" + // flags = 0
 		"DEADBEEF" // 4 hops (1-byte hash each)
 
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket error: %v", err)
 	}
@@ -365,7 +365,7 @@ func TestDecodePacket_TraceNoSNR(t *testing.T) {
 		"00" + // flags
 		"AABBCC" // 3 hops intended
 
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket error: %v", err)
 	}
@@ -389,7 +389,7 @@ func TestDecodePacket_TraceFullyCompleted(t *testing.T) {
 		"00" + // flags
 		"DDEEFF" // 3 hops intended
 
-	pkt, err := DecodePacket(hex)
+	pkt, err := DecodePacket(hex, false)
 	if err != nil {
 		t.Fatalf("DecodePacket error: %v", err)
 	}
diff --git a/cmd/server/routes.go b/cmd/server/routes.go
index cd4b65d0..e6833abf 100644
--- a/cmd/server/routes.go
+++ b/cmd/server/routes.go
@@ -930,7 +930,7 @@ func (s *Server) handleDecode(w http.ResponseWriter, r *http.Request) {
 		writeError(w, 400, "hex is required")
 		return
 	}
-	decoded, err := DecodePacket(hexStr)
+	decoded, err := DecodePacket(hexStr, true)
 	if err != nil {
 		writeError(w, 400, err.Error())
 		return
@@ -962,7 +962,7 @@ func (s *Server) handlePostPacket(w http.ResponseWriter, r *http.Request) {
 		writeError(w, 400, "hex is required")
 		return
 	}
-	decoded, err := DecodePacket(hexStr)
+	decoded, err := DecodePacket(hexStr, false)
 	if err != nil {
 		writeError(w, 400, err.Error())
 		return
diff --git a/public/packets.js b/public/packets.js
index 95a98b52..e22fc91e 100644
--- a/public/packets.js
+++ b/public/packets.js
@@ -2174,6 +2174,12 @@
         html += kv(k, String(v));
       }
     }
+    // Special handling for advert signature validation
+    if (h.payloadType === 4 && p.signatureValid !== undefined) {
+      const status = p.signatureValid ? 'Valid' : 'Invalid';
+      const badgeClass = p.signatureValid ? 'badge-success' : 'badge-danger';
+      html += kv('Signature', `<span class="badge ${badgeClass}">${status}</span>`);
+    }
     html += '</div></div>';
 
     // Raw hex