diff --git a/bitchat/Noise/NoiseProtocol.swift b/bitchat/Noise/NoiseProtocol.swift
index aa5f35be..b49baa0a 100644
--- a/bitchat/Noise/NoiseProtocol.swift
+++ b/bitchat/Noise/NoiseProtocol.swift
@@ -833,16 +833,20 @@ final class NoiseHandshakeState {
         return currentPattern >= messagePatterns.count
     }
     
-    func getTransportCiphers(useExtractedNonce: Bool) throws -> (send: NoiseCipherState, receive: NoiseCipherState) {
+    func getTransportCiphers(useExtractedNonce: Bool) throws -> (send: NoiseCipherState, receive: NoiseCipherState, handshakeHash: Data) {
         guard isHandshakeComplete() else {
             throw NoiseError.handshakeNotComplete
         }
-        
+
+        // BCH-01-010: Capture handshake hash BEFORE split() clears symmetric state
+        let finalHandshakeHash = symmetricState.getHandshakeHash()
+
         let (c1, c2) = symmetricState.split(useExtractedNonce: useExtractedNonce)
-        
+
         // Initiator uses c1 for sending, c2 for receiving
         // Responder uses c2 for sending, c1 for receiving
-        return role == .initiator ? (c1, c2) : (c2, c1)
+        let ciphers = role == .initiator ? (c1, c2) : (c2, c1)
+        return (send: ciphers.0, receive: ciphers.1, handshakeHash: finalHandshakeHash)
     }
     
     func getRemoteStaticPublicKey() -> Curve25519.KeyAgreement.PublicKey? {
diff --git a/bitchat/Noise/NoiseSession.swift b/bitchat/Noise/NoiseSession.swift
index 8c84f85a..0b96a124 100644
--- a/bitchat/Noise/NoiseSession.swift
+++ b/bitchat/Noise/NoiseSession.swift
@@ -102,23 +102,23 @@ class NoiseSession {
             
             // Check if handshake is complete
             if handshake.isHandshakeComplete() {
-                // Get transport ciphers
-                let (send, receive) = try handshake.getTransportCiphers(useExtractedNonce: true)
+                // Get transport ciphers and handshake hash (hash captured before split clears state)
+                let (send, receive, hash) = try handshake.getTransportCiphers(useExtractedNonce: true)
                 sendCipher = send
                 receiveCipher = receive
-                
+
                 // Store remote static key
                 remoteStaticPublicKey = handshake.getRemoteStaticPublicKey()
-                
+
                 // Store handshake hash for channel binding
-                handshakeHash = handshake.getHandshakeHash()
-                
+                handshakeHash = hash
+
                 state = .established
                 handshakeState = nil // Clear handshake state
-                
+
                 SecureLogger.debug("NoiseSession[\(peerID)]: Handshake complete (no response needed), transitioning to established")
                 SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
-                
+
                 return nil
             } else {
                 // Generate response
@@ -128,20 +128,20 @@ class NoiseSession {
                 
                 // Check if handshake is complete after writing
                 if handshake.isHandshakeComplete() {
-                    // Get transport ciphers
-                    let (send, receive) = try handshake.getTransportCiphers(useExtractedNonce: true)
+                    // Get transport ciphers and handshake hash (hash captured before split clears state)
+                    let (send, receive, hash) = try handshake.getTransportCiphers(useExtractedNonce: true)
                     sendCipher = send
                     receiveCipher = receive
-                    
+
                     // Store remote static key
                     remoteStaticPublicKey = handshake.getRemoteStaticPublicKey()
-                    
+
                     // Store handshake hash for channel binding
-                    handshakeHash = handshake.getHandshakeHash()
-                    
+                    handshakeHash = hash
+
                     state = .established
                     handshakeState = nil // Clear handshake state
-                    
+
                     SecureLogger.debug("NoiseSession[\(peerID)]: Handshake complete after writing response, transitioning to established")
                     SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
                 }