Encrypt private media before BLE fragmentation (#1434)

Closes the last cleartext private-content path over BLE: private DM images/voice were sent as plaintext signed fileTransfer packets, TTL-relayed across the mesh, so every relay saw the full bytes. Now the complete BitchatFilePacket is encrypted as a single Noise AEAD message (inner type 0x20, matching Android) and the opaque ciphertext is fragmented. Adds an authenticated in-session capability proof (0x21 TLV: capabilities + Ed25519 key), TOFU-style downgrade pinning, a per-send consent dialog for the signed-cleartext fallback to legacy peers, and a cancellation/admission registry so cancel/delete cannot race a deferred cleartext send.

Android wire constants (0x20 / 0x21 / capability bit 8) confirmed shipping. The 256-fragment preflight cap applies only to the directed fileTransfer migration fallback; encrypted media to capable peers uses the full receiver ceiling.

Rebased over #1428/#1349: identity reads go through BLELocalIdentityStateStore; the session-bound authenticated signing-key check and the announce-path TOFU pin are kept as complementary checks. Full local suite green (1744+197 tests).

bitchat/App/ConversationUIModel.swift

@@ -12,6 +12,7 @@ final class ConversationUIModel: ObservableObject {
     @Published private(set) var currentNickname: String
     @Published private(set) var isBatchingPublic = false
     @Published private(set) var canSendMediaInCurrentContext = true
+    @Published private(set) var legacyPrivateMediaConsentRequest: LegacyPrivateMediaConsentRequest?
     /// Who is talking live in the public mesh channel right now (floor
     /// courtesy: the composer mic tints "busy" while someone holds the floor).
     @Published private(set) var activeLiveVoiceTalker: String?
@@ -153,6 +154,13 @@ final class ConversationUIModel: ObservableObject {
         chatViewModel.sendVoiceNote(at: url)
     }
 
+    func resolveLegacyPrivateMediaConsent(requestID: UUID, approved: Bool) {
+        chatViewModel.resolveLegacyPrivateMediaConsent(
+            requestID: requestID,
+            approved: approved
+        )
+    }
+
     /// Capture backend for the mic gesture: live PTT when the current DM
     /// peer can hear it now, classic voice note otherwise.
     func makeVoiceCaptureSession() -> VoiceCaptureSession {
@@ -193,6 +201,10 @@ final class ConversationUIModel: ObservableObject {
             .receive(on: DispatchQueue.main)
             .assign(to: &$activeLiveVoiceTalker)
 
+        chatViewModel.$legacyPrivateMediaConsentRequest
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$legacyPrivateMediaConsentRequest)
+
         conversations.$activeChannel
             .receive(on: DispatchQueue.main)
             .sink { [weak self] channel in

bitchat/Identity/IdentityModels.swift

@@ -190,6 +190,18 @@ struct IdentityCache: Codable {
     // entries verified before this field exists sort as oldest)
     var verifiedAt: [String: Date]? = nil
 
+    // Stable Noise fingerprints that proved encrypted private-media support
+    // inside an authenticated Noise session. Optional for decoding caches
+    // written before this migration. Entries are monotonic until a panic wipe
+    // so an old/replayed announce cannot silently downgrade a peer.
+    var privateMediaCapableFingerprints: Set<String>? = nil
+
+    // Noise-fingerprint -> Ed25519 announcement key, learned only from the
+    // authenticated peer-state payload. This prevents a self-signed announce
+    // containing a copied public Noise key from replacing a previously bound
+    // public-message signing identity. Optional for old cache compatibility.
+    var authenticatedSigningKeysByFingerprint: [String: Data]? = nil
+
     // Fingerprint -> Cryptographic identity (noise + pinned signing key).
     // Persisting the signing-key pin is security-critical: it must survive
     // app restarts so an attacker cannot replay a known peer's
@@ -216,6 +228,8 @@ struct IdentityCache: Codable {
         vouchesByVouchee = try container.decodeIfPresent([String: [VouchRecord]].self, forKey: .vouchesByVouchee)
         vouchBatchSentAt = try container.decodeIfPresent([String: Date].self, forKey: .vouchBatchSentAt)
         verifiedAt = try container.decodeIfPresent([String: Date].self, forKey: .verifiedAt)
+        privateMediaCapableFingerprints = try container.decodeIfPresent(Set<String>.self, forKey: .privateMediaCapableFingerprints)
+        authenticatedSigningKeysByFingerprint = try container.decodeIfPresent([String: Data].self, forKey: .authenticatedSigningKeysByFingerprint)
         cryptographicIdentities = try container.decodeIfPresent([String: CryptographicIdentity].self, forKey: .cryptographicIdentities) ?? [:]
         version = try container.decodeIfPresent(Int.self, forKey: .version) ?? 1
     }

bitchat/Identity/SecureIdentityStateManager.swift

@@ -140,6 +140,14 @@ protocol SecureIdentityStateManagerProtocol {
     func markVouchBatchSent(to fingerprint: String, at date: Date)
     func signingPublicKey(forFingerprint fingerprint: String) -> Data?
     func mostRecentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String]
+
+    // MARK: Noise-authenticated announcement identity
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String)
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data?
+
+    // MARK: Private-media downgrade protection
+    func markPrivateMediaCapable(fingerprint: String)
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool
 }
 
 /// Singleton manager for secure identity state persistence and retrieval.
@@ -158,6 +166,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     
     // Thread safety
     private let queue = DispatchQueue(label: "bitchat.identity.state", attributes: .concurrent)
+    private let queueSpecificKey = DispatchSpecificKey<UInt8>()
     
     // Pending-save coalescing flag. Reads/writes are serialized on `queue`.
     //
@@ -225,6 +234,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
 
         self.encryptionKey = loadedKey
         self.encryptionKeyIsEphemeral = keyIsEphemeral
+        queue.setSpecific(key: queueSpecificKey, value: 1)
 
         // Only read the persisted cache when we hold the real key; with an
         // ephemeral key the decrypt would fail and discard the real cache.
@@ -432,6 +442,66 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
             return cache.cryptographicIdentities.values.filter { $0.fingerprint.hasPrefix(peerID.id) }
         }
     }
+
+    // MARK: - Private-media downgrade protection
+
+    func markPrivateMediaCapable(fingerprint: String) {
+        guard !fingerprint.isEmpty else { return }
+        let insertAndPersist = {
+            var pinned = self.cache.privateMediaCapableFingerprints ?? []
+            guard pinned.insert(fingerprint).inserted else { return }
+            self.cache.privateMediaCapableFingerprints = pinned
+            self.saveIdentityCache()
+        }
+        // Downgrade decisions can run immediately after an authenticated
+        // announce. Make the pin visible before returning; merely enqueueing a
+        // barrier leaves a cross-queue window where a replay can look legacy.
+        // The queue-specific fast path prevents self-deadlock if a future
+        // identity-state mutation records the capability from inside `queue`.
+        if DispatchQueue.getSpecific(key: queueSpecificKey) != nil {
+            insertAndPersist()
+        } else {
+            queue.sync(flags: .barrier, execute: insertAndPersist)
+        }
+    }
+
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool {
+        guard !fingerprint.isEmpty else { return false }
+        return queue.sync {
+            cache.privateMediaCapableFingerprints?.contains(fingerprint) == true
+        }
+    }
+
+    // MARK: - Noise-authenticated announcement identity
+
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String) {
+        guard signingPublicKey.count == AuthenticatedPeerStatePacket.signingPublicKeyLength,
+              !fingerprint.isEmpty else { return }
+        let bindAndPersist = {
+            var bindings = self.cache.authenticatedSigningKeysByFingerprint ?? [:]
+            let bindingChanged = bindings[fingerprint] != signingPublicKey
+            bindings[fingerprint] = signingPublicKey
+            self.cache.authenticatedSigningKeysByFingerprint = bindings
+            if var cryptoIdentity = self.cache.cryptographicIdentities[fingerprint] {
+                cryptoIdentity.signingPublicKey = signingPublicKey
+                self.cache.cryptographicIdentities[fingerprint] = cryptoIdentity
+            }
+            guard bindingChanged else { return }
+            self.saveIdentityCache()
+        }
+        if DispatchQueue.getSpecific(key: queueSpecificKey) != nil {
+            bindAndPersist()
+        } else {
+            queue.sync(flags: .barrier, execute: bindAndPersist)
+        }
+    }
+
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data? {
+        guard !fingerprint.isEmpty else { return nil }
+        return queue.sync {
+            cache.authenticatedSigningKeysByFingerprint?[fingerprint]
+        }
+    }
     
     func updateSocialIdentity(_ identity: SocialIdentity) {
         queue.sync(flags: .barrier) {

bitchat/Models/NoisePayload.swift

@@ -30,7 +30,7 @@ struct NoisePayload {
         
         // Safely get the first byte
         let firstByte = data[data.startIndex]
-        guard let type = NoisePayloadType(rawValue: firstByte) else {
+        guard let type = NoisePayloadType.decoded(rawValue: firstByte) else {
             return nil
         }
         

bitchat/Noise/NoiseSecurityConstants.swift

@@ -6,11 +6,30 @@
 // For more information, see <https://unlicense.org>
 //
 
+import BitFoundation
 import Foundation
 
 enum NoiseSecurityConstants {
     // Maximum message size to prevent memory exhaustion
     static let maxMessageSize = 65535 // 64KB as per Noise spec
+
+    /// The extracted transport nonce (4 bytes) and Poly1305 tag (16 bytes)
+    /// added by `NoiseCipherState` around every transport plaintext.
+    static let transportCiphertextOverhead = 20
+
+    /// Private files are an explicit BitChat extension to the ordinary Noise
+    /// message-size ceiling. They remain bounded by the same framed-file cap
+    /// used by the binary and fragment decoders. Only the `.privateFile`
+    /// typed-payload path is allowed to use this larger budget.
+    private static let privateFileOuterPacketOverhead =
+        (BinaryProtocol.v1HeaderSize + 2) // v2 adds two length bytes
+        + BinaryProtocol.senderIDSize
+        + BinaryProtocol.recipientIDSize
+    static let maxPrivateFilePlaintextSize = FileTransferLimits.maxFramedFileBytes
+        - privateFileOuterPacketOverhead
+        - transportCiphertextOverhead
+    static let maxPrivateFileCiphertextSize =
+        maxPrivateFilePlaintextSize + transportCiphertextOverhead
     
     // Maximum handshake message size
     static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern

bitchat/Noise/NoiseSecurityValidator.swift

@@ -14,6 +14,19 @@ struct NoiseSecurityValidator {
     static func validateMessageSize(_ data: Data) -> Bool {
         return data.count <= NoiseSecurityConstants.maxMessageSize
     }
+
+    static func validateCiphertextSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxMessageSize
+            + NoiseSecurityConstants.transportCiphertextOverhead
+    }
+
+    static func validatePrivateFileMessageSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxPrivateFilePlaintextSize
+    }
+
+    static func validatePrivateFileCiphertextSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxPrivateFileCiphertextSize
+    }
     
     /// Validate handshake message size
     static func validateHandshakeMessageSize(_ data: Data) -> Bool {

bitchat/Noise/NoiseSessionManager.swift

@@ -18,6 +18,10 @@ struct NoiseHandshakeProcessingResult {
 
 final class NoiseSessionManager {
     private var sessions: [PeerID: NoiseSession] = [:]
+    /// Opaque identity for each exact entry in `sessions`. The generation is
+    /// created and removed under the same barrier as the session itself, so a
+    /// caller can never authenticate data with one session and lease another.
+    private var sessionGenerations: [PeerID: UUID] = [:]
     /// A responder rehandshake must not evict a working transport session
     /// before the candidate proves that its authenticated static key belongs
     /// to the claimed wire ID. Candidates therefore live outside `sessions`
@@ -27,7 +31,7 @@ final class NoiseSessionManager {
     private let managerQueue = DispatchQueue(label: "chat.bitchat.noise.manager", attributes: .concurrent)
     
     // Callbacks
-    var onSessionEstablished: ((PeerID, Curve25519.KeyAgreement.PublicKey) -> Void)?
+    var onSessionEstablished: ((PeerID, Curve25519.KeyAgreement.PublicKey, UUID) -> Void)?
     var onSessionFailed: ((PeerID, Error) -> Void)?
     
     init(localStaticKey: Curve25519.KeyAgreement.PrivateKey, keychain: KeychainManagerProtocol) {
@@ -64,6 +68,7 @@ final class NoiseSessionManager {
             if let session = sessions.removeValue(forKey: peerID) {
                 session.reset() // Clear sensitive data before removing
             }
+            sessionGenerations.removeValue(forKey: peerID)
             if let candidate = responderCandidates.removeValue(forKey: peerID) {
                 candidate.reset()
             }
@@ -79,6 +84,7 @@ final class NoiseSessionManager {
                 candidate.reset()
             }
             sessions.removeAll()
+            sessionGenerations.removeAll()
             responderCandidates.removeAll()
         }
     }
@@ -96,12 +102,14 @@ final class NoiseSessionManager {
             // Remove any existing non-established session
             if let existingSession = sessions[peerID], !existingSession.isEstablished() {
                 _ = sessions.removeValue(forKey: peerID)
+                sessionGenerations.removeValue(forKey: peerID)
                 existingSession.reset()
             }
             
             // Create new initiator session
             let session = sessionFactory(peerID, .initiator)
             sessions[peerID] = session
+            sessionGenerations[peerID] = UUID()
             
             do {
                 let handshakeData = try session.startHandshake()
@@ -109,6 +117,7 @@ final class NoiseSessionManager {
             } catch {
                 // Clean up failed session
                 _ = sessions.removeValue(forKey: peerID)
+                sessionGenerations.removeValue(forKey: peerID)
                 session.reset()
                 SecureLogger.error(.handshakeFailed(peerID: peerID.id, error: error.localizedDescription))
                 throw error
@@ -132,8 +141,17 @@ final class NoiseSessionManager {
         from peerID: PeerID,
         message: Data
     ) throws -> NoiseHandshakeProcessingResult {
-        // Process everything within the synchronized block to prevent race conditions
-        return try managerQueue.sync(flags: .barrier) {
+        // Process everything within the synchronized block to prevent race conditions.
+        // Return establishment metadata and publish the callback only after the
+        // manager barrier is released, avoiding both a deadlock and a window in
+        // which `processHandshakeMessage` returns before authentication state.
+        let result: (
+            response: Data?,
+            establishedSession: (
+                remoteKey: Curve25519.KeyAgreement.PublicKey,
+                generation: UUID
+            )?
+        ) = try managerQueue.sync(flags: .barrier) {
             let session: NoiseSession
             let isReplacementCandidate: Bool
 
@@ -164,9 +182,11 @@ final class NoiseSessionManager {
                     // No established transport state exists to preserve. A
                     // fresh initiation replaces the incomplete handshake.
                     _ = sessions.removeValue(forKey: peerID)
+                    sessionGenerations.removeValue(forKey: peerID)
                     existing.reset()
                     let replacement = sessionFactory(peerID, .responder)
                     sessions[peerID] = replacement
+                    sessionGenerations[peerID] = UUID()
                     session = replacement
                     isReplacementCandidate = false
                 } else {
@@ -176,6 +196,7 @@ final class NoiseSessionManager {
             } else {
                 let newSession = sessionFactory(peerID, .responder)
                 sessions[peerID] = newSession
+                sessionGenerations[peerID] = UUID()
                 session = newSession
                 isReplacementCandidate = false
             }
@@ -187,8 +208,11 @@ final class NoiseSessionManager {
                 // Check the exact session that processed this message. A
                 // preserved peer-level session can remain established while a
                 // replacement candidate is still unauthenticated.
-                let didEstablishAuthenticatedSession = session.isEstablished()
-                if didEstablishAuthenticatedSession {
+                var establishedSession: (
+                    remoteKey: Curve25519.KeyAgreement.PublicKey,
+                    generation: UUID
+                )?
+                if session.isEstablished() {
                     guard let remoteKey = session.getRemoteStaticPublicKey(),
                           authenticatedRemoteKey(remoteKey, matches: peerID) else {
                         throw NoiseSessionError.peerIdentityMismatch
@@ -197,22 +221,18 @@ final class NoiseSessionManager {
                     if isReplacementCandidate {
                         _ = responderCandidates.removeValue(forKey: peerID)
                         let previous = sessions.updateValue(session, forKey: peerID)
+                        sessionGenerations[peerID] = UUID()
                         if let previous, previous !== session {
                             previous.reset()
                         }
                     }
-
-                    // Schedule callback outside the synchronized block to prevent deadlock
-                    DispatchQueue.global().async { [weak self] in
-                        self?.onSessionEstablished?(peerID, remoteKey)
+                    guard let generation = sessionGenerations[peerID] else {
+                        throw NoiseEncryptionError.sessionNotEstablished
                     }
+                    establishedSession = (remoteKey, generation)
                 }
                 
-                return NoiseHandshakeProcessingResult(
-                    response: response,
-                    didEstablishAuthenticatedSession:
-                        didEstablishAuthenticatedSession
-                )
+                return (response, establishedSession)
             } catch {
                 // A failed candidate is discarded without touching the
                 // established session. Ordinary failed handshakes retain the
@@ -225,6 +245,7 @@ final class NoiseSessionManager {
                 } else if let storedSession = sessions[peerID],
                           storedSession === session {
                     _ = sessions.removeValue(forKey: peerID)
+                    sessionGenerations.removeValue(forKey: peerID)
                 }
                 session.reset()
                 
@@ -237,6 +258,14 @@ final class NoiseSessionManager {
                 throw error
             }
         }
+
+        if let established = result.establishedSession {
+            onSessionEstablished?(peerID, established.remoteKey, established.generation)
+        }
+        return NoiseHandshakeProcessingResult(
+            response: result.response,
+            didEstablishAuthenticatedSession: result.establishedSession != nil
+        )
     }
 
     /// Mesh handshakes normally use a 16-hex wire ID. Full Noise-key IDs are
@@ -260,19 +289,74 @@ final class NoiseSessionManager {
     // MARK: - Encryption/Decryption
     
     func encrypt(_ plaintext: Data, for peerID: PeerID) throws -> Data {
-        guard let session = getSession(for: peerID) else {
-            throw NoiseSessionError.sessionNotFound
+        try managerQueue.sync {
+            guard let session = sessions[peerID] else {
+                throw NoiseSessionError.sessionNotFound
+            }
+            return try session.encrypt(plaintext)
+        }
+    }
+
+    /// Encrypts only if `expected` still names the current established entry.
+    /// A rekey between capability proof and media encryption therefore fails
+    /// closed instead of sending on an unproven replacement session.
+    func encrypt(
+        _ plaintext: Data,
+        for peerID: PeerID,
+        expectedSessionGeneration expected: UUID
+    ) throws -> Data {
+        try managerQueue.sync {
+            guard let session = sessions[peerID],
+                  session.isEstablished(),
+                  sessionGenerations[peerID] == expected else {
+                throw NoiseEncryptionError.sessionNotEstablished
+            }
+            return try session.encrypt(plaintext)
         }
-        
-        return try session.encrypt(plaintext)
     }
     
     func decrypt(_ ciphertext: Data, from peerID: PeerID) throws -> Data {
-        guard let session = getSession(for: peerID) else {
-            throw NoiseSessionError.sessionNotFound
+        try decryptWithSessionGeneration(ciphertext, from: peerID).plaintext
+    }
+
+    func sessionGeneration(for peerID: PeerID) -> UUID? {
+        managerQueue.sync {
+            guard sessions[peerID]?.isEstablished() == true else { return nil }
+            return sessionGenerations[peerID]
+        }
+    }
+
+    /// Decrypts while holding the manager's read lease. Session promotion and
+    /// removal require its barrier, so the returned generation always names
+    /// the exact session object that authenticated these bytes.
+    func decryptWithSessionGeneration(
+        _ ciphertext: Data,
+        from peerID: PeerID
+    ) throws -> (plaintext: Data, sessionGeneration: UUID) {
+        try managerQueue.sync {
+            guard let session = sessions[peerID] else {
+                throw NoiseSessionError.sessionNotFound
+            }
+            guard session.isEstablished(),
+                  let generation = sessionGenerations[peerID] else {
+                throw NoiseEncryptionError.sessionNotEstablished
+            }
+            return (try session.decrypt(ciphertext), generation)
+        }
+    }
+
+    /// Runs a state commit under a read lease for the exact established
+    /// session. Rekey, replacement, and removal all need the same barrier.
+    func withCurrentSessionGeneration<Result>(
+        for peerID: PeerID,
+        expected: UUID,
+        _ body: () -> Result
+    ) -> Result? {
+        managerQueue.sync {
+            guard sessions[peerID]?.isEstablished() == true,
+                  sessionGenerations[peerID] == expected else { return nil }
+            return body()
         }
-        
-        return try session.decrypt(ciphertext)
     }
     
     // MARK: - Key Management
@@ -299,11 +383,11 @@ final class NoiseSessionManager {
         }
     }
     
-    func initiateRekey(for peerID: PeerID) throws {
+    func initiateRekey(for peerID: PeerID) throws -> Data {
         // Remove old session
         removeSession(for: peerID)
         
         // Initiate new handshake
-        _ = try initiateHandshake(with: peerID)
+        return try initiateHandshake(with: peerID)
     }
 }

bitchat/Noise/SecureNoiseSession.swift

@@ -24,8 +24,12 @@ final class SecureNoiseSession: NoiseSession {
             throw NoiseSecurityError.sessionExhausted
         }
         
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(plaintext) else {
+        // Ordinary Noise messages keep the protocol ceiling. Finalized media
+        // is the sole typed-payload extension and remains under the framed-file
+        // cap enforced again at the service and file-decoder layers.
+        let isPrivateFile = NoisePayloadType.isPrivateFile(rawValue: plaintext.first)
+            && NoiseSecurityValidator.validatePrivateFileMessageSize(plaintext)
+        guard NoiseSecurityValidator.validateMessageSize(plaintext) || isPrivateFile else {
             throw NoiseSecurityError.messageTooLarge
         }
         
@@ -42,8 +46,11 @@ final class SecureNoiseSession: NoiseSession {
             throw NoiseSecurityError.sessionExpired
         }
         
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(ciphertext) else {
+        // The payload type is encrypted, so a large candidate can only be
+        // bounded here; `NoiseEncryptionService.decrypt` authenticates it and
+        // then requires the resulting type to be `.privateFile`.
+        guard NoiseSecurityValidator.validateCiphertextSize(ciphertext)
+                || NoiseSecurityValidator.validatePrivateFileCiphertextSize(ciphertext) else {
             throw NoiseSecurityError.messageTooLarge
         }
         

bitchat/Protocols/BitchatProtocol.swift

@@ -79,12 +79,35 @@ enum NoisePayloadType: UInt8 {
     case groupKeyUpdate = 0x07      // Creator-signed group state (key rotation / roster update)
     // Live voice (push-to-talk)
     case voiceFrame = 0x08          // One live voice-burst packet (see VoiceBurstPacket)
+    // Finalized private media. `0x20` is the value already deployed by the
+    // Android client. The complete BitchatFilePacket is encrypted inside
+    // Noise before the outer noiseEncrypted packet is fragmented.
+    case privateFile = 0x20
+    // Versioned peer state authenticated by the surrounding Noise session.
+    // This is intentionally distinct from the public announce: announce
+    // capabilities are discovery hints, while this payload proves possession
+    // of the advertised Noise static key before downgrade state is pinned.
+    case authenticatedPeerState = 0x21
     // Verification (QR-based OOB binding)
     case verifyChallenge = 0x10     // Verification challenge
     case verifyResponse  = 0x11     // Verification response
     // Transitive verification (web of trust)
     case vouch = 0x12               // Batch of vouch attestations
 
+    /// #1434 briefly used 0x09 before release. Accept it while prerelease
+    /// builds age out, but never emit it. Decoders canonicalize both values to
+    /// `.privateFile` so the compatibility alias cannot leak into app logic.
+    static let prereleasePrivateFileRawValue: UInt8 = 0x09
+
+    static func decoded(rawValue: UInt8) -> NoisePayloadType? {
+        rawValue == prereleasePrivateFileRawValue ? .privateFile : Self(rawValue: rawValue)
+    }
+
+    static func isPrivateFile(rawValue: UInt8?) -> Bool {
+        guard let rawValue else { return false }
+        return rawValue == privateFile.rawValue || rawValue == prereleasePrivateFileRawValue
+    }
+
     var description: String {
         switch self {
         case .privateMessage: return "privateMessage"
@@ -93,6 +116,8 @@ enum NoisePayloadType: UInt8 {
         case .groupInvite: return "groupInvite"
         case .groupKeyUpdate: return "groupKeyUpdate"
         case .voiceFrame: return "voiceFrame"
+        case .privateFile: return "privateFile"
+        case .authenticatedPeerState: return "authenticatedPeerState"
         case .verifyChallenge: return "verifyChallenge"
         case .verifyResponse: return "verifyResponse"
         case .vouch: return "vouch"

bitchat/Protocols/Packets.swift

@@ -156,6 +156,89 @@ struct AnnouncementPacket {
     }
 }
 
+/// State that is authoritative only because it is carried inside an
+/// established Noise session. The public announce remains useful for
+/// discovery, but its self-signature cannot prove possession of the copied
+/// Noise public key it contains.
+///
+/// Wire format (v1):
+/// `[version=0x01][type][length][value]...`
+/// - TLV `0x01`: canonical minimal little-endian `PeerCapabilities`
+/// - TLV `0x02`: 32-byte Ed25519 signing public key
+///
+/// Unknown TLVs are skipped for forward compatibility. Unknown versions,
+/// duplicates, non-canonical capability fields, and malformed lengths are
+/// rejected without changing authenticated state.
+struct AuthenticatedPeerStatePacket: Equatable {
+    static let currentVersion: UInt8 = 1
+    static let signingPublicKeyLength = 32
+
+    let capabilities: PeerCapabilities
+    let signingPublicKey: Data
+
+    private enum TLVType: UInt8 {
+        case capabilities = 0x01
+        case signingPublicKey = 0x02
+    }
+
+    func encode() -> Data? {
+        guard signingPublicKey.count == Self.signingPublicKeyLength else { return nil }
+        let capabilityBytes = capabilities.encoded()
+        guard !capabilityBytes.isEmpty, capabilityBytes.count <= 8 else { return nil }
+
+        var data = Data([Self.currentVersion])
+        data.append(TLVType.capabilities.rawValue)
+        data.append(UInt8(capabilityBytes.count))
+        data.append(capabilityBytes)
+        data.append(TLVType.signingPublicKey.rawValue)
+        data.append(UInt8(signingPublicKey.count))
+        data.append(signingPublicKey)
+        return data
+    }
+
+    static func decode(from data: Data) -> AuthenticatedPeerStatePacket? {
+        guard data.first == Self.currentVersion else { return nil }
+
+        var offset = 1
+        var capabilities: PeerCapabilities?
+        var signingPublicKey: Data?
+
+        while offset < data.count {
+            guard offset + 2 <= data.count else { return nil }
+            let typeRaw = data[offset]
+            let length = Int(data[offset + 1])
+            offset += 2
+            guard offset + length <= data.count else { return nil }
+            let value = Data(data[offset..<(offset + length)])
+            offset += length
+
+            guard let type = TLVType(rawValue: typeRaw) else {
+                continue
+            }
+            switch type {
+            case .capabilities:
+                guard capabilities == nil,
+                      !value.isEmpty,
+                      value.count <= 8 else { return nil }
+                let decoded = PeerCapabilities(encoded: value)
+                guard decoded.encoded() == value else { return nil }
+                capabilities = decoded
+
+            case .signingPublicKey:
+                guard signingPublicKey == nil,
+                      value.count == Self.signingPublicKeyLength else { return nil }
+                signingPublicKey = value
+            }
+        }
+
+        guard let capabilities, let signingPublicKey else { return nil }
+        return AuthenticatedPeerStatePacket(
+            capabilities: capabilities,
+            signingPublicKey: signingPublicKey
+        )
+    }
+}
+
 struct PrivateMessagePacket {
     let messageID: String
     let content: String

bitchat/Protocols/PeerCapabilities+Local.swift

@@ -3,5 +3,5 @@ import BitFoundation
 extension PeerCapabilities {
     /// Capabilities this build advertises in its announce packets.
     /// Each feature adds its bit here when it ships.
-    static let localSupported: PeerCapabilities = [.vouch, .prekeys, .groups]
+    static let localSupported: PeerCapabilities = [.vouch, .prekeys, .groups, .privateMedia]
 }

bitchat/Services/BLE/BLEAnnounceHandler.swift

@@ -22,6 +22,9 @@ struct BLEAnnounceHandlerEnvironment {
     /// eviction; this fallback keeps the TOFU signing-key pin effective for
     /// returning peers.
     let persistedSigningPublicKey: (PeerID) -> Data?
+    /// Ed25519 key previously bound to this Noise identity by an authenticated
+    /// peer-state payload, if any (persistent identity-state read).
+    let authenticatedSigningPublicKey: (_ noisePublicKey: Data) -> Data?
     /// Verifies the packet signature against the announced signing key.
     let verifySignature: (_ packet: BitchatPacket, _ signingPublicKey: Data) -> Bool
     /// Direct link state for the peer (BLE-queue read).
@@ -149,6 +152,9 @@ final class BLEAnnounceHandler {
             existingNoisePublicKey: existingPeerKeys.noisePublicKey,
             announcedNoisePublicKey: announcement.noisePublicKey,
             existingSigningPublicKey: existingPeerKeys.signingPublicKey,
+            authenticatedSigningPublicKey: env.authenticatedSigningPublicKey(
+                announcement.noisePublicKey
+            ),
             announcedSigningPublicKey: announcement.signingPublicKey
         )
         if case .reject(.keyMismatch) = trustDecision {
@@ -157,6 +163,12 @@ final class BLEAnnounceHandler {
         if case .reject(.signingKeyMismatch) = trustDecision {
             SecureLogger.warning("🚨 Announce signing-key mismatch for \(peerID.id.prefix(8))… — refusing to replace pinned signing key (possible impersonation attempt)", category: .security)
         }
+        if case .reject(.authenticatedSigningKeyMismatch) = trustDecision {
+            SecureLogger.warning(
+                "⚠️ Announce signing-key replacement rejected for Noise-authenticated peer \(peerID.id.prefix(8))…",
+                category: .security
+            )
+        }
         var verifiedAnnounce = trustDecision.isVerified
 
         var isNewPeer = false

bitchat/Services/BLE/BLEAnnounceHandlingPolicy.swift

@@ -57,6 +57,7 @@ enum BLEAnnounceTrustRejection: Equatable {
     case invalidSignature
     case keyMismatch
     case signingKeyMismatch
+    case authenticatedSigningKeyMismatch
 }
 
 enum BLEAnnounceTrustDecision: Equatable {
@@ -74,13 +75,22 @@ enum BLEAnnounceTrustPolicy {
         signatureValid: Bool,
         existingNoisePublicKey: Data?,
         announcedNoisePublicKey: Data,
-        existingSigningPublicKey: Data?,
+        existingSigningPublicKey: Data? = nil,
+        authenticatedSigningPublicKey: Data? = nil,
         announcedSigningPublicKey: Data
     ) -> BLEAnnounceTrustDecision {
         if let existingNoisePublicKey, existingNoisePublicKey != announcedNoisePublicKey {
             return .reject(.keyMismatch)
         }
 
+        // Strongest binding first: an Ed25519 key bound to this Noise identity
+        // inside an authenticated Noise session can never be replaced by a
+        // merely self-signed announce.
+        if let authenticatedSigningPublicKey,
+           announcedSigningPublicKey != authenticatedSigningPublicKey {
+            return .reject(.authenticatedSigningKeyMismatch)
+        }
+
         // TOFU signing-key pinning. The packet signature only proves the
         // announce is self-consistent — it is verified against the Ed25519 key
         // carried *inside the same announce*. Since peerIDs derive from the

bitchat/Services/BLE/BLEFileTransferHandler.swift

@@ -16,6 +16,8 @@ struct BLEFileTransferHandlerEnvironment {
     let peersSnapshot: () -> [PeerID: BLEPeerInfo]
     /// Verifies a packet's signature against a candidate signing key (registry path).
     let verifyPacketSignature: (_ packet: BitchatPacket, _ signingPublicKey: Data) -> Bool
+    /// Local signing key used to authenticate our own gossip-sync replays.
+    let localSigningPublicKey: () -> Data
     /// Resolves a display name from a verified packet signature for peers missing from the registry.
     let signedSenderDisplayName: (_ packet: BitchatPacket, _ peerID: PeerID) -> String?
     /// Tracks the broadcast file packet for gossip sync.
@@ -46,54 +48,105 @@ final class BLEFileTransferHandler {
         self.environment = environment
     }
 
-    /// Returns `false` when the packet fails sender authentication and must
-    /// not be relayed onward. Every other outcome returns `true`: files
-    /// directed to another peer are forwarded untouched, and local-only drops
-    /// (malformed payload, quota, save failure) don't affect multi-hop
-    /// delivery to nodes that may handle them fine.
+    /// Returns `false` when the raw packet fails sender authentication (or is
+    /// a live self-echo) and must not be relayed onward. Authentication runs
+    /// before the routing decision, so a forged directed packet cannot use a
+    /// node that is not its recipient as an unsigned forwarding hop.
     @discardableResult
     func handle(_ packet: BitchatPacket, from peerID: PeerID) -> Bool {
         let env = environment
-        if BLEFileTransferPolicy.isSelfEcho(packet: packet, from: peerID, localPeerID: env.localPeerID()) { return true }
-
-        guard let deliveryPlan = BLEFileTransferPolicy.deliveryPlan(packet: packet, localPeerID: env.localPeerID()) else {
-            return true
-        }
-
+        let localPeerID = env.localPeerID()
         let peersSnapshot = env.peersSnapshot()
-        guard let senderNickname = resolveSenderNickname(
+
+        guard let senderNickname = authenticatedRawSenderNickname(
             packet: packet,
             from: peerID,
-            isBroadcast: !deliveryPlan.isPrivateMessage,
             peers: peersSnapshot,
             env: env
         ) else {
-            SecureLogger.warning("🚫 Dropping file transfer from unverified or unknown peer \(peerID.id.prefix(8))…", category: .security)
+            SecureLogger.warning("🚫 Dropping raw file transfer with missing/invalid signature from \(peerID.id.prefix(8))…", category: .security)
             return false
         }
 
+        if BLEFileTransferPolicy.isSelfEcho(packet: packet, from: peerID, localPeerID: localPeerID) {
+            return false
+        }
+
+        guard let deliveryPlan = BLEFileTransferPolicy.deliveryPlan(packet: packet, localPeerID: localPeerID) else {
+            return true
+        }
+
         if deliveryPlan.shouldTrackForSync {
             env.trackPacketSeen(packet)
         }
 
+        _ = storeIncomingPayload(
+            packet.payload,
+            from: peerID,
+            senderNickname: senderNickname,
+            timestamp: Date(timeIntervalSince1970: Double(packet.timestamp) / 1000),
+            isPrivate: deliveryPlan.isPrivateMessage,
+            env: env
+        )
+        // Once authenticated, a local decode/quota/save failure is not proof
+        // that downstream nodes should be denied the valid signed packet.
+        return true
+    }
+
+    /// Accepts a file packet only after it has been authenticated and
+    /// decrypted by the peer's Noise session. The inner packet deliberately
+    /// has no redundant signature: Noise supplies sender authentication and
+    /// confidentiality, while this handler retains the same validation,
+    /// quota, persistence, and UI-delivery behavior as public files.
+    @discardableResult
+    func handlePrivatePayload(_ payload: Data, from peerID: PeerID, timestamp: Date) -> Bool {
+        let env = environment
+        let peers = env.peersSnapshot()
+        let senderNickname = BLEPeerSenderDisplayName.resolveKnownPeer(
+            peerID: peerID,
+            localPeerID: env.localPeerID(),
+            localNickname: env.localNickname(),
+            peers: peers,
+            allowConnectedUnverified: true
+        ) ?? BLEPeerSenderDisplayName.anonymousNickname(for: peerID)
+
+        return storeIncomingPayload(
+            payload,
+            from: peerID,
+            senderNickname: senderNickname,
+            timestamp: timestamp,
+            isPrivate: true,
+            env: env
+        )
+    }
+
+    private func storeIncomingPayload(
+        _ payload: Data,
+        from peerID: PeerID,
+        senderNickname: String,
+        timestamp: Date,
+        isPrivate: Bool,
+        env: BLEFileTransferHandlerEnvironment
+    ) -> Bool {
+
         let filePacket: BitchatFilePacket
         let mime: MimeType
-        switch BLEIncomingFileValidator.validate(payload: packet.payload) {
+        switch BLEIncomingFileValidator.validate(payload: payload) {
         case .success(let acceptance):
             filePacket = acceptance.filePacket
             mime = acceptance.mime
         case .failure(.malformedPayload):
             SecureLogger.error("❌ Failed to decode file transfer payload", category: .session)
-            return true
+            return false
         case .failure(.payloadTooLarge(let bytes)):
             SecureLogger.warning("🚫 Dropping file transfer exceeding size cap (\(bytes) bytes)", category: .security)
-            return true
+            return false
         case .failure(.unsupportedMime(let mimeType, let bytes)):
             SecureLogger.warning("🚫 MIME REJECT: '\(mimeType ?? "<empty>")' not supported. Size=\(bytes)b from \(peerID.id.prefix(8))...", category: .security)
-            return true
+            return false
         case .failure(.magicMismatch(let mime, let bytes, let prefixHex)):
             SecureLogger.warning("🚫 MAGIC REJECT: MIME='\(mime)' size=\(bytes)b prefix=[\(prefixHex)] from \(peerID.id.prefix(8))...", category: .security)
-            return true
+            return false
         }
 
         // BCH-01-002: Enforce storage quota before saving
@@ -106,28 +159,27 @@ final class BLEFileTransferHandler {
             mime.defaultExtension,
             mime.category.rawValue
         ) else {
-            return true
+            return false
         }
 
-        if deliveryPlan.isPrivateMessage {
+        if isPrivate {
             env.updatePeerLastSeen(peerID)
         }
 
-        let ts = Date(timeIntervalSince1970: Double(packet.timestamp) / 1000)
         let message = BitchatMessage(
             sender: senderNickname,
             content: "\(mime.category.messagePrefix)\(destination.lastPathComponent)",
-            timestamp: ts,
+            timestamp: timestamp,
             isRelay: false,
             originalSender: nil,
-            isPrivate: deliveryPlan.isPrivateMessage,
+            isPrivate: isPrivate,
             recipientNickname: nil,
             senderPeerID: peerID,
             // Received messages need an explicit status: BitchatMessage
             // defaults private messages to .sending, which the media views
             // render as an in-flight send (empty reveal mask, disabled tap).
-            deliveryStatus: deliveryPlan.isPrivateMessage
-                ? .delivered(to: env.localNickname(), at: ts)
+            deliveryStatus: isPrivate
+                ? .delivered(to: env.localNickname(), at: timestamp)
                 : nil
         )
 
@@ -137,51 +189,38 @@ final class BLEFileTransferHandler {
         return true
     }
 
-    /// Resolves the authenticated display name for a file transfer's sender.
-    ///
-    /// Directed (private) transfers are addressed to us specifically and keep
-    /// the lenient connected-peer path. Broadcast transfers carry an
-    /// attacker-controllable `senderID` exactly like public messages and public
-    /// voice frames — registry membership alone is NOT proof of identity, so a
-    /// valid packet signature from the claimed sender is required before we
-    /// trust it. Without this, a peer that observed a public voice burst could
-    /// spoof a broadcast `voice_<burstID>.m4a` note under the talker's ID and
-    /// overwrite the signature-verified live bubble with attacker audio.
-    private func resolveSenderNickname(
+    /// Every remaining raw file transfer is signed, regardless of whether it
+    /// is broadcast, addressed to us, or merely passing through. Registry
+    /// signing keys are preferred; persisted identities cover peers that have
+    /// rotated or are not currently present in the registry.
+    private func authenticatedRawSenderNickname(
         packet: BitchatPacket,
         from peerID: PeerID,
-        isBroadcast: Bool,
         peers: [PeerID: BLEPeerInfo],
         env: BLEFileTransferHandlerEnvironment
     ) -> String? {
-        guard isBroadcast else {
-            return BLEPeerSenderDisplayName.resolveKnownPeer(
-                peerID: peerID,
-                localPeerID: env.localPeerID(),
-                localNickname: env.localNickname(),
-                peers: peers,
-                allowConnectedUnverified: true
-            ) ?? env.signedSenderDisplayName(packet, peerID)
-        }
+        guard packet.signature != nil else { return nil }
 
-        // Our own broadcasts replayed back via gossip sync (ttl==0) are
-        // trivially authentic and cannot be verified against the peer registry
-        // or identity cache, so exempt self exactly as `BLEPublicMessageHandler`
-        // does. Verify against the signing key already in the
-        // (synchronously-updated) registry first, then fall back to the
-        // persisted-identity signature lookup for peers not yet cached there.
-        let isSelf = peerID == env.localPeerID()
-        let registrySigningKey = peers[peerID]?.signingPublicKey
-        let verifiedViaRegistry = !isSelf && (registrySigningKey.map { env.verifyPacketSignature(packet, $0) } ?? false)
-        let signedDisplayName = (isSelf || verifiedViaRegistry) ? nil : env.signedSenderDisplayName(packet, peerID)
-        guard isSelf || verifiedViaRegistry || signedDisplayName != nil else { return nil }
+        let localPeerID = env.localPeerID()
+        let candidateKey = peerID == localPeerID
+            ? env.localSigningPublicKey()
+            : peers[peerID]?.signingPublicKey
+        let verifiedWithKnownKey = candidateKey.map {
+            env.verifyPacketSignature(packet, $0)
+        } ?? false
+        let signedDisplayName = verifiedWithKnownKey
+            ? nil
+            : env.signedSenderDisplayName(packet, peerID)
+        guard verifiedWithKnownKey || signedDisplayName != nil else { return nil }
 
         return BLEPeerSenderDisplayName.resolveKnownPeer(
             peerID: peerID,
-            localPeerID: env.localPeerID(),
+            localPeerID: localPeerID,
             localNickname: env.localNickname(),
             peers: peers,
-            allowConnectedUnverified: false
-        ) ?? signedDisplayName
+            // The packet signature authenticates the announced peer; the old
+            // connected-but-unsigned leniency is not involved.
+            allowConnectedUnverified: true
+        ) ?? signedDisplayName ?? BLEPeerSenderDisplayName.anonymousNickname(for: peerID)
     }
 }

bitchat/Services/BLE/BLEFragmentAssemblyBuffer.swift

@@ -201,8 +201,11 @@ struct BLEFragmentAssemblyBuffer {
     }
 
     private static func assemblyLimit(for originalType: UInt8) -> Int {
-        if originalType == MessageType.fileTransfer.rawValue {
+        if originalType == MessageType.fileTransfer.rawValue
+            || originalType == MessageType.noiseEncrypted.rawValue {
             // Allow headroom for TLV metadata and binary framing overhead.
+            // A large noiseEncrypted packet can be an E2E-encrypted private
+            // file; its authenticated plaintext is validated after decrypt.
             return FileTransferLimits.maxFramedFileBytes
         }
 

bitchat/Services/BLE/BLENoisePacketHandler.swift

@@ -7,6 +7,11 @@ struct BLENoiseHandshakeHandlingResult {
     let didEstablishAuthenticatedSession: Bool
 }
 
+struct BLENoiseDecryptionResult {
+    let plaintext: Data
+    let sessionGeneration: UUID
+}
+
 /// Narrow environment for `BLENoisePacketHandler`.
 ///
 /// All queue hops (collections barrier writes, main-actor UI notification)
@@ -35,9 +40,16 @@ struct BLENoisePacketHandlerEnvironment {
     /// Updates the registry last-seen timestamp for the peer (async barrier write).
     let updatePeerLastSeen: (PeerID) -> Void
     /// Decrypts an encrypted payload from the peer (crypto).
-    let decrypt: (_ payload: Data, _ peerID: PeerID) throws -> Data
+    let decrypt: (_ payload: Data, _ peerID: PeerID) throws -> BLENoiseDecryptionResult
     /// Clears the peer's Noise session after an unrecoverable decrypt failure (crypto).
     let clearSession: (PeerID) -> Void
+    /// Consumes session-authenticated protocol state inside the transport. It
+    /// must never escape to UI or Nostr payload dispatch.
+    let handleAuthenticatedPeerState: (
+        _ peerID: PeerID,
+        _ payload: Data,
+        _ sessionGeneration: UUID
+    ) -> Void
     /// Delivers `.noisePayloadReceived` to the UI as one main-actor hop.
     let deliverNoisePayload: (
         _ peerID: PeerID,
@@ -146,20 +158,30 @@ final class BLENoisePacketHandler {
         env.updatePeerLastSeen(peerID)
 
         do {
-            let decrypted = try env.decrypt(packet.payload, peerID)
+            let decryption = try env.decrypt(packet.payload, peerID)
+            let decrypted = decryption.plaintext
             guard decrypted.count > 0 else { return }
 
             // First byte indicates the payload type
             let payloadType = decrypted[0]
             let payloadData = decrypted.dropFirst()
 
-            guard let noisePayloadType = NoisePayloadType(rawValue: payloadType) else {
+            guard let noisePayloadType = NoisePayloadType.decoded(rawValue: payloadType) else {
                 SecureLogger.warning("⚠️ Unknown noise payload type: \(payloadType)")
                 return
             }
 
             SecureLogger.debug("🔐 Decrypted noise payload type \(noisePayloadType.description) from \(peerID.id.prefix(8))…", category: .session)
 
+            if noisePayloadType == .authenticatedPeerState {
+                env.handleAuthenticatedPeerState(
+                    peerID,
+                    Data(payloadData),
+                    decryption.sessionGeneration
+                )
+                return
+            }
+
             let ts = Date(timeIntervalSince1970: Double(packet.timestamp) / 1000)
             env.deliverNoisePayload(peerID, noisePayloadType, Data(payloadData), ts)
         } catch NoiseEncryptionError.sessionNotEstablished {

bitchat/Services/BLE/BLENoisePayloadFactory.swift

@@ -17,6 +17,16 @@ enum BLENoisePayloadFactory {
         typedPayload(.delivered, payload: Data(messageID.utf8))
     }
 
+    static func privateFile(_ filePacket: BitchatFilePacket) -> Data? {
+        guard let payload = filePacket.encode() else { return nil }
+        return typedPayload(.privateFile, payload: payload)
+    }
+
+    static func authenticatedPeerState(_ state: AuthenticatedPeerStatePacket) -> Data? {
+        guard let payload = state.encode() else { return nil }
+        return typedPayload(.authenticatedPeerState, payload: payload)
+    }
+
     static func typedPayload(_ type: NoisePayloadType, payload: Data) -> Data {
         var typed = Data([type.rawValue])
         typed.append(payload)

bitchat/Services/BLE/BLENoiseSessionQueues.swift

@@ -6,9 +6,16 @@ struct BLEPendingPrivateMessage: Equatable {
     let messageID: String
 }
 
+struct BLEPendingTypedPayload: Equatable {
+    let payload: Data
+    /// Present for app-initiated media so handshake queuing preserves the
+    /// fragment scheduler's progress/cancellation identity.
+    let transferId: String?
+}
+
 struct BLENoiseSessionQueues {
     private var privateMessagesByPeerID: [PeerID: [BLEPendingPrivateMessage]] = [:]
-    private var typedPayloadsByPeerID: [PeerID: [Data]] = [:]
+    private var typedPayloadsByPeerID: [PeerID: [BLEPendingTypedPayload]] = [:]
 
     var isEmpty: Bool {
         privateMessagesByPeerID.isEmpty && typedPayloadsByPeerID.isEmpty
@@ -34,13 +41,35 @@ struct BLENoiseSessionQueues {
         privateMessagesByPeerID[peerID, default: []].insert(contentsOf: messages, at: 0)
     }
 
-    mutating func appendTypedPayload(_ payload: Data, for peerID: PeerID) {
-        typedPayloadsByPeerID[peerID, default: []].append(payload)
+    mutating func appendTypedPayload(_ payload: Data, transferId: String? = nil, for peerID: PeerID) {
+        typedPayloadsByPeerID[peerID, default: []].append(
+            BLEPendingTypedPayload(payload: payload, transferId: transferId)
+        )
     }
 
-    mutating func takeTypedPayloads(for peerID: PeerID) -> [Data] {
+    mutating func takeTypedPayloads(for peerID: PeerID) -> [BLEPendingTypedPayload] {
         let payloads = typedPayloadsByPeerID[peerID] ?? []
         typedPayloadsByPeerID.removeValue(forKey: peerID)
         return payloads
     }
+
+    func containsTypedPayload(transferId: String) -> Bool {
+        typedPayloadsByPeerID.values.contains { payloads in
+            payloads.contains { $0.transferId == transferId }
+        }
+    }
+
+    @discardableResult
+    mutating func removeTypedPayload(transferId: String) -> Bool {
+        for peerID in Array(typedPayloadsByPeerID.keys) {
+            guard var payloads = typedPayloadsByPeerID[peerID],
+                  let index = payloads.firstIndex(where: { $0.transferId == transferId }) else {
+                continue
+            }
+            payloads.remove(at: index)
+            typedPayloadsByPeerID[peerID] = payloads.isEmpty ? nil : payloads
+            return true
+        }
+        return false
+    }
 }

bitchat/Services/BLE/BLEOutboundFragmentPlanner.swift

@@ -17,6 +17,9 @@ struct BLEOutboundFragmentPlan {
 }
 
 enum BLEOutboundFragmentPlanner {
+    /// Current Android receivers reject fragment sets above 256. Private
+    /// media v1 treats that deployed ceiling as a cross-platform contract.
+    static let privateMediaV1MaxFragments = 256
     private static let minimumChunkSize = 64
     private static let fragmentIDLength = 8
 
@@ -71,6 +74,10 @@ enum BLEOutboundFragmentPlanner {
         )
     }
 
+    static func isPrivateMediaV1Compatible(_ plan: BLEOutboundFragmentPlan) -> Bool {
+        plan.totalFragments <= privateMediaV1MaxFragments
+    }
+
     private static func sizingPolicy(
         for packet: BitchatPacket,
         requestedMaxChunk: Int?,

bitchat/Services/BLE/BLEOutboundFragmentTransferScheduler.swift

@@ -29,8 +29,9 @@ struct BLEOutboundFragmentTransferRequest {
     }
 
     var resolvedTransferId: String? {
+        if let transferId { return transferId }
         guard packet.type == MessageType.fileTransfer.rawValue else { return nil }
-        return transferId ?? packet.payload.sha256Hex()
+        return packet.payload.sha256Hex()
     }
 
     /// Content identity independent of the caller-chosen transfer ID: the

bitchat/Services/BLE/BLEPeerRegistry.swift

@@ -10,6 +10,9 @@ struct BLEPeerInfo: Equatable {
     var isVerifiedNickname: Bool
     var lastSeen: Date
     var capabilities: PeerCapabilities = []
+    /// Distinguishes an old client that omitted the capabilities TLV from a
+    /// modern client that explicitly advertised a set without a given bit.
+    var capabilitiesWereExplicitlyAdvertised: Bool = false
     /// Rendezvous cell from the peer's announce when it advertises `.bridge`.
     var bridgeGeohash: String?
 }
@@ -114,6 +117,10 @@ struct BLEPeerRegistry {
         peers[peerID.toShort()]?.capabilities ?? []
     }
 
+    func capabilitiesWereExplicitlyAdvertised(for peerID: PeerID) -> Bool {
+        peers[peerID.toShort()]?.capabilitiesWereExplicitlyAdvertised == true
+    }
+
     /// Peers whose last verified announce advertised the given capability.
     func peers(advertising capability: PeerCapabilities) -> [PeerID] {
         peers.values.filter { $0.capabilities.contains(capability) }.map(\.peerID)
@@ -174,6 +181,14 @@ struct BLEPeerRegistry {
         peers[peerID] = peer
     }
 
+    /// Replaces the announcement signing key only after the surrounding Noise
+    /// session proved possession of this peer's static key.
+    mutating func bindAuthenticatedSigningPublicKey(_ key: Data, for peerID: PeerID) {
+        guard var peer = peers[peerID.toShort()] else { return }
+        peer.signingPublicKey = key
+        peers[peer.peerID] = peer
+    }
+
     /// Applies a verified announce to the registry.
     ///
     /// TOFU signing-key pinning: once a signing key has been bound to this
@@ -189,7 +204,7 @@ struct BLEPeerRegistry {
         signingPublicKey: Data?,
         isConnected: Bool,
         now: Date,
-        capabilities: PeerCapabilities = [],
+        capabilities: PeerCapabilities? = nil,
         bridgeGeohash: String? = nil
     ) -> BLEPeerAnnounceUpdate? {
         let existing = peers[peerID]
@@ -215,7 +230,8 @@ struct BLEPeerRegistry {
             signingPublicKey: signingPublicKey ?? existing?.signingPublicKey,
             isVerifiedNickname: true,
             lastSeen: now,
-            capabilities: capabilities,
+            capabilities: capabilities ?? [],
+            capabilitiesWereExplicitlyAdvertised: capabilities != nil,
             bridgeGeohash: bridgeGeohash
         )
 

bitchat/Services/NoiseEncryptionService.swift

@@ -165,7 +165,6 @@ final class NoiseEncryptionService {
     // Peer fingerprints (SHA256 hash of static public key)
     private var peerFingerprints: [PeerID: String] = [:]
     private var fingerprintToPeerID: [String: PeerID] = [:]
-    
     // Thread safety
     private let serviceQueue = DispatchQueue(label: "chat.bitchat.noise.service", attributes: .concurrent)
     
@@ -183,12 +182,18 @@ final class NoiseEncryptionService {
     
     // Callbacks
     private var onPeerAuthenticatedHandlers: [((PeerID, String) -> Void)] = [] // Array of handlers for peer authentication
+    private var onPeerAuthenticatedWithGenerationHandlers: [((PeerID, String, UUID) -> Void)] = []
     var onHandshakeRequired: ((PeerID) -> Void)? // peerID needs handshake
+    /// Automatic rekey removed the old session and produced XX message 1.
+    /// The transport must clear session-scoped state and put these exact bytes
+    /// on the wire; merely reporting "handshake required" strands the partial
+    /// initiator session because a second initiate call sees it already exists.
+    var onRekeyHandshakeReady: ((_ peerID: PeerID, _ message: Data) -> Void)?
     
     // Add a handler for peer authentication
     func addOnPeerAuthenticatedHandler(_ handler: @escaping (PeerID, String) -> Void) {
-        serviceQueue.async(flags: .barrier) { [weak self] in
-            self?.onPeerAuthenticatedHandlers.append(handler)
+        serviceQueue.sync(flags: .barrier) {
+            onPeerAuthenticatedHandlers.append(handler)
         }
     }
     
@@ -201,6 +206,18 @@ final class NoiseEncryptionService {
             }
         }
     }
+
+    /// Generation-aware authentication notifications are used by protocols
+    /// whose state must be bound to one exact Noise transport session.
+    var onPeerAuthenticatedWithGeneration: ((PeerID, String, UUID) -> Void)? {
+        get { nil }
+        set {
+            guard let handler = newValue else { return }
+            serviceQueue.sync(flags: .barrier) {
+                onPeerAuthenticatedWithGenerationHandlers.append(handler)
+            }
+        }
+    }
     
     init(keychain: KeychainManagerProtocol) {
         self.keychain = keychain
@@ -295,8 +312,12 @@ final class NoiseEncryptionService {
         self.sessionManager = NoiseSessionManager(localStaticKey: staticIdentityKey, keychain: keychain)
 
         // Set up session callbacks
-        sessionManager.onSessionEstablished = { [weak self] peerID, remoteStaticKey in
-            self?.handleSessionEstablished(peerID: peerID, remoteStaticKey: remoteStaticKey)
+        sessionManager.onSessionEstablished = { [weak self] peerID, remoteStaticKey, generation in
+            self?.handleSessionEstablished(
+                peerID: peerID,
+                remoteStaticKey: remoteStaticKey,
+                sessionGeneration: generation
+            )
         }
 
         // Start session maintenance timer
@@ -740,11 +761,56 @@ final class NoiseEncryptionService {
         
         return try sessionManager.encrypt(data, for: peerID)
     }
+
+    /// Encrypts a finalized private-media packet. Ordinary Noise application
+    /// messages retain the 64 KiB ceiling; this purpose-specific path permits
+    /// the bounded `BitchatFilePacket` envelope and refuses every other typed
+    /// payload so the larger allocation budget cannot become a generic bypass.
+    func encryptPrivateFilePayload(
+        _ data: Data,
+        for peerID: PeerID,
+        sessionGeneration: UUID? = nil
+    ) throws -> Data {
+        guard NoisePayloadType.isPrivateFile(rawValue: data.first),
+              NoiseSecurityValidator.validatePrivateFileMessageSize(data) else {
+            throw NoiseSecurityError.messageTooLarge
+        }
+
+        guard rateLimiter.allowMessage(from: peerID) else {
+            throw NoiseSecurityError.rateLimitExceeded
+        }
+
+        guard hasEstablishedSession(with: peerID) else {
+            onHandshakeRequired?(peerID)
+            throw NoiseEncryptionError.handshakeRequired
+        }
+
+        // `maxPrivateFilePlaintextSize` already subtracts the cipher's fixed
+        // nonce/tag overhead, so the result is bounded without a second copy.
+        if let sessionGeneration {
+            return try sessionManager.encrypt(
+                data,
+                for: peerID,
+                expectedSessionGeneration: sessionGeneration
+            )
+        }
+        return try sessionManager.encrypt(data, for: peerID)
+    }
     
     /// Decrypt data from a specific peer
     func decrypt(_ data: Data, from peerID: PeerID) throws -> Data {
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(data) else {
+        try decryptWithSessionGeneration(data, from: peerID).plaintext
+    }
+
+    func decryptWithSessionGeneration(
+        _ data: Data,
+        from peerID: PeerID
+    ) throws -> (plaintext: Data, sessionGeneration: UUID) {
+        // Standard transport ciphertext has 20 bytes of nonce/tag overhead.
+        // A larger candidate is admitted only up to the framed-file ceiling;
+        // after authenticated decryption it must prove it is `.privateFile`.
+        let isStandardCiphertext = NoiseSecurityValidator.validateCiphertextSize(data)
+        guard isStandardCiphertext || NoiseSecurityValidator.validatePrivateFileCiphertextSize(data) else {
             throw NoiseSecurityError.messageTooLarge
         }
         
@@ -758,7 +824,14 @@ final class NoiseEncryptionService {
             throw NoiseEncryptionError.sessionNotEstablished
         }
         
-        return try sessionManager.decrypt(data, from: peerID)
+        let result = try sessionManager.decryptWithSessionGeneration(data, from: peerID)
+        if !isStandardCiphertext {
+            guard NoisePayloadType.isPrivateFile(rawValue: result.plaintext.first),
+                  NoiseSecurityValidator.validatePrivateFileMessageSize(result.plaintext) else {
+                throw NoiseSecurityError.messageTooLarge
+            }
+        }
+        return result
     }
     
     // MARK: - Peer Management
@@ -770,6 +843,25 @@ final class NoiseEncryptionService {
         }
     }
 
+    func sessionGeneration(for peerID: PeerID) -> UUID? {
+        sessionManager.sessionGeneration(for: peerID)
+    }
+
+    /// Runs `body` while holding a read lease on the exact session generation.
+    /// Session insertion, replacement, and removal use the same manager
+    /// barrier, so they cannot interleave with an authenticated-state commit.
+    func withCurrentSessionGeneration<Result>(
+        for peerID: PeerID,
+        expected: UUID,
+        _ body: () -> Result
+    ) -> Result? {
+        sessionManager.withCurrentSessionGeneration(
+            for: peerID,
+            expected: expected,
+            body
+        )
+    }
+
     func clearEphemeralStateForPanic() {
         sessionManager.removeAllSessions()
         serviceQueue.sync(flags: .barrier) {
@@ -792,24 +884,36 @@ final class NoiseEncryptionService {
     
     // MARK: - Private Helpers
     
-    private func handleSessionEstablished(peerID: PeerID, remoteStaticKey: Curve25519.KeyAgreement.PublicKey) {
+    private func handleSessionEstablished(
+        peerID: PeerID,
+        remoteStaticKey: Curve25519.KeyAgreement.PublicKey,
+        sessionGeneration: UUID
+    ) {
         // Calculate fingerprint
         let fingerprint = remoteStaticKey.rawRepresentation.sha256Fingerprint()
         
-        // Store fingerprint mapping
-        serviceQueue.sync(flags: .barrier) {
+        // Registering handlers is synchronous, and this barrier snapshots them
+        // with the fingerprint update. Invoke the snapshot outside the queue:
+        // parallel Swift Testing workers must not block behind queued callback
+        // registration or allow a handler to re-enter serviceQueue.
+        let handlers: (
+            generationAware: [(PeerID, String, UUID) -> Void],
+            legacy: [(PeerID, String) -> Void]
+        ) = serviceQueue.sync(flags: .barrier) {
             peerFingerprints[peerID] = fingerprint
             fingerprintToPeerID[fingerprint] = peerID
+            return (onPeerAuthenticatedWithGenerationHandlers, onPeerAuthenticatedHandlers)
         }
         
         // Log security event
         SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
         
-        // Notify all handlers about authentication
-        serviceQueue.async { [weak self] in
-            self?.onPeerAuthenticatedHandlers.forEach { handler in
-                handler(peerID, fingerprint)
-            }
+        // Notify all handlers about authentication.
+        handlers.generationAware.forEach { handler in
+            handler(peerID, fingerprint, sessionGeneration)
+        }
+        handlers.legacy.forEach { handler in
+            handler(peerID, fingerprint)
         }
     }
         
@@ -830,19 +934,26 @@ final class NoiseEncryptionService {
         let sessionsNeedingRekey = sessionManager.getSessionsNeedingRekey()
         
         for (peerID, needsRekey) in sessionsNeedingRekey where needsRekey {
-            
-            // Attempt to rekey the session
             do {
-                try sessionManager.initiateRekey(for: peerID)
-                SecureLogger.debug("Key rotation initiated for peer: \(peerID)", category: .security)
-                
-                // Signal that handshake is needed
-                onHandshakeRequired?(peerID)
+                try initiateAutomaticRekey(for: peerID)
             } catch {
                 SecureLogger.error(error, context: "Failed to initiate rekey for peer: \(peerID)", category: .session)
             }
         }
     }
+
+    private func initiateAutomaticRekey(for peerID: PeerID) throws {
+        let handshakeMessage = try sessionManager.initiateRekey(for: peerID)
+        SecureLogger.debug("Key rotation initiated for peer: \(peerID)", category: .security)
+        onRekeyHandshakeReady?(peerID, handshakeMessage)
+        onHandshakeRequired?(peerID)
+    }
+
+    #if DEBUG
+    func _test_initiateAutomaticRekey(for peerID: PeerID) throws {
+        try initiateAutomaticRekey(for: peerID)
+    }
+    #endif
     
     deinit {
         stopRekeyTimer()

bitchat/Services/TransferProgressManager.swift

@@ -11,6 +11,7 @@ final class TransferProgressManager {
         case updated(id: String, sentFragments: Int, totalFragments: Int)
         case completed(id: String, totalFragments: Int)
         case cancelled(id: String, sentFragments: Int, totalFragments: Int)
+        case rejected(id: String, reason: String)
     }
 
     private let subject = PassthroughSubject<Event, Never>()
@@ -49,6 +50,17 @@ final class TransferProgressManager {
         }
     }
 
+    /// Fails a preflight check while keeping the outgoing placeholder visible
+    /// with an actionable reason instead of treating policy/size rejection as
+    /// a user cancellation.
+    func rejectBeforeStart(id: String, reason: String) {
+        queue.async(flags: .barrier) { [weak self] in
+            guard let self = self else { return }
+            self.states.removeValue(forKey: id)
+            self.subject.send(.rejected(id: id, reason: reason))
+        }
+    }
+
     func snapshot(id: String) -> (sent: Int, total: Int)? {
         var result: (sent: Int, total: Int)?
         queue.sync {

bitchat/Services/Transport.swift

@@ -83,6 +83,20 @@ enum TransportEvent: @unchecked Sendable {
     case bluetoothStateUpdated(CBManagerState)
 }
 
+/// Downgrade-safe decision for a private-media recipient. Callers ask before
+/// prompting, and BLEService checks again when it consumes any one-shot
+/// legacy consent.
+enum PrivateMediaSendPolicy: Equatable {
+    case encrypted
+    /// A public announce hinted at encrypted media (or a prior authenticated
+    /// pin exists), but this exact Noise session has not yet supplied its
+    /// authenticated peer-state proof. Callers wait boundedly; they must not
+    /// pre-queue encrypted bytes or silently select the legacy path.
+    case awaitingCapabilityProof
+    case legacyRequiresConsent
+    case blockedDowngrade
+}
+
 protocol TransportEventDelegate: AnyObject {
     @MainActor func didReceiveTransportEvent(_ event: TransportEvent)
 }
@@ -163,6 +177,12 @@ protocol Transport: AnyObject {
     func sendDeliveryAck(for messageID: String, to peerID: PeerID)
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String)
     func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String)
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    )
     func cancelTransfer(_ transferId: String)
 
     // Live voice / push-to-talk (mesh transports only): one encoded
@@ -208,6 +228,11 @@ protocol Transport: AnyObject {
     /// Capabilities the peer advertised in its last verified announce;
     /// empty for peers that predate the capabilities TLV.
     func peerCapabilities(_ peerID: PeerID) -> PeerCapabilities
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    )
     /// Sends an encoded vouch-attestation batch inside the Noise session.
     func sendVouchAttestations(_ payload: Data, to peerID: PeerID)
     /// Appends a peer-authenticated observer. Unlike
@@ -278,6 +303,16 @@ extension Transport {
     func sendGroupKeyUpdate(_ statePayload: Data, to peerID: PeerID) {}
     func broadcastGroupMessage(_ envelope: Data) {}
     func peerCapabilities(_ peerID: PeerID) -> PeerCapabilities { [] }
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy { .blockedDowngrade }
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    ) {
+        let policy = privateMediaSendPolicy(to: peerID)
+        Task { @MainActor in
+            completion(policy == .awaitingCapabilityProof ? .blockedDowngrade : policy)
+        }
+    }
     func sendVouchAttestations(_ payload: Data, to peerID: PeerID) {}
     func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void) {}
     func sendCourierMessage(_ content: String, messageID: String, recipientNoiseKey: Data, via couriers: [PeerID]) -> Bool { false }
@@ -294,6 +329,15 @@ extension Transport {
     func currentMeshTopology() -> MeshTopologySnapshot? { nil }
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {}
     func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {}
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    ) {
+        guard !allowLegacyFallback else { return }
+        sendFilePrivate(packet, to: peerID, transferId: transferId)
+    }
     func cancelTransfer(_ transferId: String) {}
 
     func sendMessage(_ content: String, mentions: [String], messageID: String, timestamp: Date) {

bitchat/Services/TransportConfig.swift

@@ -9,6 +9,12 @@ enum TransportConfig {
     static let bleMaxInFlightAssemblies: Int = 128          // Cap concurrent fragment assemblies
     static let bleHighDegreeThreshold: Int = 6              // For adaptive TTL/probabilistic relays
     static let bleMaxConcurrentTransfers: Int = 2           // Limit simultaneous large media sends
+    // Bounded wait for the session-authenticated capability proof used by
+    // private-media migration. Expiry never auto-sends clear bytes; it only
+    // resolves to the existing one-shot consent or downgrade-blocked path.
+    static let privateMediaCapabilityProofTimeoutSeconds: TimeInterval = 5
+    static let privateMediaCapabilityProofPendingPeerCap: Int = 64
+    static let privateMediaCapabilityProofWaitersPerPeerCap: Int = 16
     static let bleFragmentRelayMinDelayMs: Int = 8          // Faster forwarding for media fragments
     static let bleFragmentRelayMaxDelayMs: Int = 25         // Upper jitter bound for fragment relays
     // Fragment relay TTL in sparse graphs; matches messageTTLDefault so media

bitchat/ViewModels/ChatMediaTransferCoordinator.swift

@@ -6,6 +6,19 @@ import Foundation
 import UIKit
 #endif
 
+struct LegacyPrivateMediaConsentRequest: Identifiable, Equatable {
+    let id: UUID
+    let peerID: PeerID
+    let peerName: String
+    let transferId: String
+    let messageID: String
+}
+
+struct PendingLegacyPrivateMediaConsent {
+    let request: LegacyPrivateMediaConsentRequest
+    let completion: @MainActor (Bool) -> Void
+}
+
 /// The narrow surface `ChatMediaTransferCoordinator` needs from its owner.
 ///
 /// Follows the `ChatDeliveryContext` exemplar: the coordinator depends on the
@@ -43,7 +56,24 @@ protocol ChatMediaTransferContext: AnyObject {
     func recordContentKey(_ key: String, timestamp: Date)
 
     // MARK: Mesh file transfer
-    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String)
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    )
+    func requestLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    )
+    func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String)
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    )
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String)
     func cancelTransfer(_ transferId: String)
 }
@@ -59,8 +89,50 @@ extension ChatViewModel: ChatMediaTransferContext {
     // other contexts or satisfied by existing `ChatViewModel` members. The
     // members below flatten mesh service accesses.
 
-    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {
-        meshService.sendFilePrivate(packet, to: peerID, transferId: transferId)
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy {
+        meshService.privateMediaSendPolicy(to: peerID)
+    }
+
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    ) {
+        meshService.resolvePrivateMediaSendPolicy(to: peerID, completion: completion)
+    }
+
+    func requestLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    ) {
+        enqueueLegacyPrivateMediaConsent(
+            for: peerID,
+            transferId: transferId,
+            messageID: messageID,
+            completion: completion
+        )
+    }
+
+    func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String) {
+        invalidateLegacyPrivateMediaConsent(
+            transferId: transferId,
+            messageID: messageID
+        )
+    }
+
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    ) {
+        meshService.sendFilePrivate(
+            packet,
+            to: peerID,
+            transferId: transferId,
+            allowLegacyFallback: allowLegacyFallback
+        )
     }
 
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {
@@ -152,6 +224,7 @@ final class ChatMediaTransferCoordinator {
     private unowned let context: any ChatMediaTransferContext
     private let prepareImagePacket: @Sendable (URL) throws -> ChatPreparedImage
     private let imagePreparationBarrier = ImagePreparationBarrier()
+    private let prepareVoiceNotePacket: @Sendable (URL) throws -> BitchatFilePacket
 
     private(set) var transferIdToMessageIDs: [String: [String]] = [:]
     private(set) var messageIDToTransferId: [String: String] = [:]
@@ -160,10 +233,14 @@ final class ChatMediaTransferCoordinator {
         context: any ChatMediaTransferContext,
         prepareImagePacket: @escaping @Sendable (URL) throws -> ChatPreparedImage = {
             try ChatMediaPreparation.prepareImagePacket(from: $0)
+        },
+        prepareVoiceNotePacket: @escaping @Sendable (URL) throws -> BitchatFilePacket = {
+            try ChatMediaPreparation.prepareVoiceNotePacket(at: $0)
         }
     ) {
         self.context = context
         self.prepareImagePacket = prepareImagePacket
+        self.prepareVoiceNotePacket = prepareVoiceNotePacket
     }
 
     func sendVoiceNote(at url: URL) {
@@ -181,22 +258,33 @@ final class ChatMediaTransferCoordinator {
         )
         let messageID = message.id
         let transferId = makeTransferID(messageID: messageID)
-        let generation = imagePreparationBarrier.currentGeneration
+        // Own the transfer before detached preparation begins. Cancel/delete
+        // must be able to invalidate this exact invocation even while file I/O
+        // is still running off the main actor.
+        registerTransfer(transferId: transferId, messageID: messageID)
+        let prepareVoiceNotePacket = self.prepareVoiceNotePacket
+        let barrier = imagePreparationBarrier
+        let generation = barrier.currentGeneration
 
-        Task.detached(priority: .userInitiated) { [weak self] in
+        Task.detached(priority: .userInitiated) { [weak self, barrier] in
             do {
                 let packet = try await runBlockingMediaPreparation {
-                    try ChatMediaPreparation.prepareVoiceNotePacket(at: url)
+                    try prepareVoiceNotePacket(url)
                 }
 
-                await MainActor.run { [weak self] in
+                await MainActor.run { [weak self, barrier] in
                     guard let self,
-                          self.imagePreparationBarrier.isCurrent(generation) else {
+                          barrier.isCurrent(generation),
+                          self.isRegisteredTransfer(transferId, messageID: messageID) else {
                         return
                     }
-                    self.registerTransfer(transferId: transferId, messageID: messageID)
                     if let peerID = targetPeer {
-                        self.context.sendFilePrivate(packet, to: peerID, transferId: transferId)
+                        self.beginPrivateMediaSend(
+                            packet,
+                            to: peerID,
+                            transferId: transferId,
+                            messageID: messageID
+                        )
                     } else {
                         self.context.sendFileBroadcast(packet, transferId: transferId)
                     }
@@ -204,18 +292,20 @@ final class ChatMediaTransferCoordinator {
             } catch ChatMediaPreparationError.voiceNoteTooLarge(let size) {
                 SecureLogger.warning("Voice note exceeds size limit (\(size) bytes)", category: .session)
                 try? FileManager.default.removeItem(at: url)
-                await MainActor.run { [weak self] in
+                await MainActor.run { [weak self, barrier] in
                     guard let self,
-                          self.imagePreparationBarrier.isCurrent(generation) else {
+                          barrier.isCurrent(generation),
+                          self.isRegisteredTransfer(transferId, messageID: messageID) else {
                         return
                     }
                     self.handleMediaSendFailure(messageID: messageID, reason: String(localized: "content.delivery.reason.voice_too_large", comment: "Failure reason shown when a voice note exceeds the size limit"))
                 }
             } catch {
                 SecureLogger.error("Voice note send failed: \(error)", category: .session)
-                await MainActor.run { [weak self] in
+                await MainActor.run { [weak self, barrier] in
                     guard let self,
-                          self.imagePreparationBarrier.isCurrent(generation) else {
+                          barrier.isCurrent(generation),
+                          self.isRegisteredTransfer(transferId, messageID: messageID) else {
                         return
                     }
                     self.handleMediaSendFailure(messageID: messageID, reason: String(localized: "content.delivery.reason.voice_send_failed", comment: "Failure reason shown when a voice note could not be sent"))
@@ -337,7 +427,12 @@ final class ChatMediaTransferCoordinator {
                     let transferId = self.makeTransferID(messageID: messageID)
                     self.registerTransfer(transferId: transferId, messageID: messageID)
                     if let peerID = targetPeer {
-                        self.context.sendFilePrivate(prepared.packet, to: peerID, transferId: transferId)
+                        self.beginPrivateMediaSend(
+                            prepared.packet,
+                            to: peerID,
+                            transferId: transferId,
+                            messageID: messageID
+                        )
                     } else {
                         self.context.sendFileBroadcast(prepared.packet, transferId: transferId)
                     }
@@ -403,17 +498,127 @@ final class ChatMediaTransferCoordinator {
         return message
     }
 
+    private func beginPrivateMediaSend(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        messageID: String
+    ) {
+        continuePrivateMediaSend(
+            packet,
+            to: peerID,
+            transferId: transferId,
+            messageID: messageID,
+            policy: context.privateMediaSendPolicy(to: peerID)
+        )
+    }
+
+    private func continuePrivateMediaSend(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        policy: PrivateMediaSendPolicy
+    ) {
+        switch policy {
+        case .encrypted:
+            context.sendFilePrivate(
+                packet,
+                to: peerID,
+                transferId: transferId,
+                allowLegacyFallback: false
+            )
+
+        case .awaitingCapabilityProof:
+            context.resolvePrivateMediaSendPolicy(to: peerID) { [weak self] resolvedPolicy in
+                guard let self,
+                      self.isRegisteredTransfer(transferId, messageID: messageID) else {
+                    return
+                }
+                guard resolvedPolicy != .awaitingCapabilityProof else {
+                    self.handleMediaSendFailure(
+                        messageID: messageID,
+                        reason: String(
+                            localized: "content.delivery.reason.private_media_capability_unresolved",
+                            defaultValue: "Could not confirm encrypted media support",
+                            comment: "Failure reason when private-media capability negotiation did not resolve"
+                        )
+                    )
+                    return
+                }
+                self.continuePrivateMediaSend(
+                    packet,
+                    to: peerID,
+                    transferId: transferId,
+                    messageID: messageID,
+                    policy: resolvedPolicy
+                )
+            }
+
+        case .legacyRequiresConsent:
+            context.requestLegacyPrivateMediaConsent(
+                for: peerID,
+                transferId: transferId,
+                messageID: messageID
+            ) { [weak self] approved in
+                guard let self else { return }
+                // Consent belongs to this exact placeholder/transfer. A late
+                // dialog callback after cancel/delete must never resurrect it.
+                guard self.messageIDToTransferId[messageID] == transferId,
+                      self.transferIdToMessageIDs[transferId]?.contains(messageID) == true else {
+                    return
+                }
+                guard approved else {
+                    self.handleMediaSendFailure(
+                        messageID: messageID,
+                        reason: String(
+                            localized: "content.delivery.reason.legacy_media_declined",
+                            defaultValue: "Not sent without end-to-end encryption",
+                            comment: "Failure reason after declining the warning for a legacy clear private-media send"
+                        )
+                    )
+                    return
+                }
+                self.context.sendFilePrivate(
+                    packet,
+                    to: peerID,
+                    transferId: transferId,
+                    allowLegacyFallback: true
+                )
+            }
+
+        case .blockedDowngrade:
+            handleMediaSendFailure(
+                messageID: messageID,
+                reason: String(
+                    localized: "content.delivery.reason.private_media_downgrade_blocked",
+                    defaultValue: "Encrypted media required; ask this contact to upgrade",
+                    comment: "Failure reason when a peer that previously supported encrypted media appears to downgrade"
+                )
+            )
+        }
+    }
+
     func registerTransfer(transferId: String, messageID: String) {
         transferIdToMessageIDs[transferId, default: []].append(messageID)
         messageIDToTransferId[messageID] = transferId
     }
 
+    private func isRegisteredTransfer(_ transferId: String, messageID: String) -> Bool {
+        messageIDToTransferId[messageID] == transferId
+            && transferIdToMessageIDs[transferId]?.contains(messageID) == true
+    }
+
     func makeTransferID(messageID: String) -> String {
         "\(messageID)-\(UUID().uuidString)"
     }
 
     func clearTransferMapping(for messageID: String) {
         guard let transferId = messageIDToTransferId.removeValue(forKey: messageID) else { return }
+        context.cancelLegacyPrivateMediaConsent(
+            transferId: transferId,
+            messageID: messageID
+        )
         guard var queue = transferIdToMessageIDs[transferId] else { return }
 
         if !queue.isEmpty {
@@ -448,6 +653,9 @@ final class ChatMediaTransferCoordinator {
             guard let messageID = transferIdToMessageIDs[id]?.first else { return }
             clearTransferMapping(for: messageID)
             context.removeMessage(withID: messageID, cleanupFile: true)
+        case .rejected(let id, let reason):
+            guard let messageID = transferIdToMessageIDs[id]?.first else { return }
+            handleMediaSendFailure(messageID: messageID, reason: reason)
         }
     }
 
@@ -488,6 +696,13 @@ final class ChatMediaTransferCoordinator {
     }
 
     func deleteMediaMessage(messageID: String) {
+        // Delete is also a send cancellation. In particular, an approved
+        // legacy-clear send may still be waiting on BLEService.messageQueue;
+        // removing only the UI mapping would let that deferred work transmit.
+        if let transferId = messageIDToTransferId[messageID],
+           transferIdToMessageIDs[transferId]?.first == messageID {
+            context.cancelTransfer(transferId)
+        }
         clearTransferMapping(for: messageID)
         context.removeMessage(withID: messageID, cleanupFile: true)
     }

bitchat/ViewModels/ChatTransportEventCoordinator.swift

@@ -407,6 +407,13 @@ private extension ChatTransportEventCoordinator {
 
         case .voiceFrame:
             context.handleVoiceFramePayload(from: peerID, payload: payload, timestamp: timestamp)
+
+        case .privateFile, .authenticatedPeerState:
+            // BLEService validates and persists decrypted private files before
+            // emitting a normal `.messageReceived` event, and consumes peer
+            // state inside the transport. Neither payload crosses this
+            // UI-facing typed-payload fallback.
+            break
         }
     }
 

bitchat/ViewModels/ChatViewModel.swift

@@ -375,6 +375,8 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     @Published var showBluetoothAlert = false
     @Published var bluetoothAlertMessage = ""
     @Published var bluetoothState: CBManagerState = .unknown
+    @Published private(set) var legacyPrivateMediaConsentRequest: LegacyPrivateMediaConsentRequest?
+    private var pendingLegacyPrivateMediaConsents: [PendingLegacyPrivateMediaConsent] = []
 
     private func performDeliveryUpdate(_ update: @escaping @MainActor (ChatDeliveryCoordinator) -> Void) {
         if Thread.isMainThread {
@@ -1268,6 +1270,10 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         mediaTransferCoordinator.resetForPanic()
         liveVoiceCoordinator.resetForPanic()
 
+        // Deny and release any clear-media confirmations before identities,
+        // message state, and local files are wiped.
+        cancelAllLegacyPrivateMediaConsents()
+
         // Clear all messages (public timelines and private chats live in the
         // single-writer ConversationStore; the derived `messages` view and
         // the legacy mirror empty with it)
@@ -1936,4 +1942,91 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         publicConversationCoordinator.sendHapticFeedback(for: message)
     }
 }
+
+@MainActor
+extension ChatViewModel {
+    func enqueueLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    ) {
+        let request = LegacyPrivateMediaConsentRequest(
+            id: UUID(),
+            peerID: peerID,
+            peerName: nicknameForPeer(peerID),
+            transferId: transferId,
+            messageID: messageID
+        )
+        pendingLegacyPrivateMediaConsents.append(PendingLegacyPrivateMediaConsent(
+            request: request,
+            completion: completion
+        ))
+        if legacyPrivateMediaConsentRequest == nil {
+            legacyPrivateMediaConsentRequest = request
+        }
+    }
+
+    func resolveLegacyPrivateMediaConsent(requestID: UUID, approved: Bool) {
+        // SwiftUI may report both the selected button and the presentation
+        // binding's dismissal. Resolve only the exact request that was shown;
+        // a duplicate callback for it must not consume the next queued send.
+        guard legacyPrivateMediaConsentRequest?.id == requestID,
+              pendingLegacyPrivateMediaConsents.first?.request.id == requestID else {
+            return
+        }
+        let resolved = pendingLegacyPrivateMediaConsents.removeFirst()
+        // Drive the boolean presentation state through false before showing
+        // the next queued per-send warning. Otherwise SwiftUI sees true→true,
+        // closes the first dialog, and never presents the second.
+        legacyPrivateMediaConsentRequest = nil
+        resolved.completion(approved)
+        presentNextLegacyPrivateMediaConsentDeferred()
+    }
+
+    func invalidateLegacyPrivateMediaConsent(transferId: String, messageID: String) {
+        let invalidatedIDs = Set(
+            pendingLegacyPrivateMediaConsents.compactMap { pending -> UUID? in
+                let request = pending.request
+                return request.transferId == transferId && request.messageID == messageID
+                    ? request.id
+                    : nil
+            }
+        )
+        guard !invalidatedIDs.isEmpty else { return }
+
+        pendingLegacyPrivateMediaConsents.removeAll {
+            invalidatedIDs.contains($0.request.id)
+        }
+        if let currentID = legacyPrivateMediaConsentRequest?.id,
+           invalidatedIDs.contains(currentID) {
+            legacyPrivateMediaConsentRequest = nil
+            presentNextLegacyPrivateMediaConsentDeferred()
+        }
+    }
+
+    func cancelAllLegacyPrivateMediaConsents() {
+        let pending = pendingLegacyPrivateMediaConsents
+        pendingLegacyPrivateMediaConsents.removeAll()
+        legacyPrivateMediaConsentRequest = nil
+        for item in pending {
+            item.completion(false)
+        }
+    }
+
+    private func presentNextLegacyPrivateMediaConsentDeferred() {
+        guard legacyPrivateMediaConsentRequest == nil,
+              let nextRequestID = pendingLegacyPrivateMediaConsents.first?.request.id else {
+            return
+        }
+        DispatchQueue.main.async { [weak self] in
+            guard let self,
+                  self.legacyPrivateMediaConsentRequest == nil,
+                  self.pendingLegacyPrivateMediaConsents.first?.request.id == nextRequestID else {
+                return
+            }
+            self.legacyPrivateMediaConsentRequest = self.pendingLegacyPrivateMediaConsents[0].request
+        }
+    }
+}
 // End of ChatViewModel class

bitchat/ViewModels/NostrInboundPipeline.swift

@@ -397,7 +397,7 @@ final class NostrInboundPipeline {
             // claiming to be group traffic over Nostr is ignored.
             // Live voice is mesh-only: latency and relay cost make it
             // meaningless over Nostr.
-            case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame:
+            case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame, .privateFile, .authenticatedPeerState:
                 break
             }
         }
@@ -489,7 +489,7 @@ final class NostrInboundPipeline {
                         // in v1; group traffic over Nostr is ignored.
                         // Live voice is mesh-only: latency and relay cost make it
                         // meaningless over Nostr.
-                        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame:
+                        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame, .privateFile, .authenticatedPeerState:
                             break
                         }
                     }

bitchat/Views/ContentSheetViews.swift

@@ -36,6 +36,7 @@ struct ContentPeopleSheetView: View {
     #endif
 
     var body: some View {
+        let legacyConsentRequest = conversationUIModel.legacyPrivateMediaConsentRequest
         NavigationStack {
             Group {
                 if privateConversationModel.selectedPeerID != nil {
@@ -97,6 +98,63 @@ struct ContentPeopleSheetView: View {
         }
         .themedSheetBackground()
         .foregroundColor(palette.primary)
+        .confirmationDialog(
+            String(
+                localized: "content.private_media.legacy_warning.title",
+                defaultValue: "Send without end-to-end encryption?",
+                comment: "Title warning before sending private media to an older client in a clear signed envelope"
+            ),
+            isPresented: Binding(
+                get: { legacyConsentRequest != nil },
+                set: { isPresented in
+                    if !isPresented, let requestID = legacyConsentRequest?.id {
+                        conversationUIModel.resolveLegacyPrivateMediaConsent(
+                            requestID: requestID,
+                            approved: false
+                        )
+                    }
+                }
+            ),
+            titleVisibility: .visible
+        ) {
+            Button(
+                String(
+                    localized: "content.private_media.legacy_warning.send",
+                    defaultValue: "send visible file",
+                    comment: "Destructive confirmation action for one legacy clear private-media send"
+                ),
+                role: .destructive
+            ) {
+                if let requestID = legacyConsentRequest?.id {
+                    conversationUIModel.resolveLegacyPrivateMediaConsent(
+                        requestID: requestID,
+                        approved: true
+                    )
+                }
+            }
+            Button("common.cancel", role: .cancel) {
+                if let requestID = legacyConsentRequest?.id {
+                    conversationUIModel.resolveLegacyPrivateMediaConsent(
+                        requestID: requestID,
+                        approved: false
+                    )
+                }
+            }
+        } message: {
+            if let request = legacyConsentRequest {
+                Text(
+                    String(
+                        format: String(
+                            localized: "content.private_media.legacy_warning.message",
+                            defaultValue: "%@'s client does not advertise encrypted private media. This file will be signed but not end-to-end encrypted, so mesh relays can see it. Send this file anyway?",
+                            comment: "Warning explaining the confidentiality loss for one legacy private-media send; parameter is the peer name"
+                        ),
+                        locale: .current,
+                        request.peerName
+                    )
+                )
+            }
+        }
         #if os(macOS)
         .frame(minWidth: 420, minHeight: 520)
         #endif