diff --git a/frontend/src/tools/nachrichten.jsx b/frontend/src/tools/nachrichten.jsx
index 71e1575..7f76917 100644
--- a/frontend/src/tools/nachrichten.jsx
+++ b/frontend/src/tools/nachrichten.jsx
@@ -4,6 +4,7 @@ import { UserIcon, TrashIcon } from '../icons.jsx';
 import {
   getOrCreateKeyPair,
   getPublicKeyJwk,
+  getFingerprint,
   deriveSharedKey,
   encryptMsg,
   decryptMsg,
@@ -17,6 +18,7 @@ export default function Nachrichten({ toast, mobile }) {
   const [messages,    setMessages]    = useState([]);
   const [sharedKey,   setSharedKey]   = useState(null);   // null | CryptoKey | 'error'
   const [decrypted,   setDecrypted]   = useState({});
+  const [partnerFp,   setPartnerFp]   = useState('');
   const [text,        setText]        = useState('');
   const [sending,     setSending]     = useState(false);
   const bottomRef = useRef(null);
@@ -45,16 +47,22 @@ export default function Nachrichten({ toast, mobile }) {
     return () => clearInterval(pollRef.current);
   }, [activeUser?.id]);
 
-  // ── Shared Key ───────────────────────────────────────────────────────────────
+  // ── Shared Key + Partner-Fingerprint ─────────────────────────────────────────
   useEffect(() => {
     setSharedKey(null);
     setDecrypted({});
+    setPartnerFp('');
     if (!kp || !activeUser?.public_key) return;
     try {
       const pubJwk = JSON.parse(activeUser.public_key);
       deriveSharedKey(kp.privateKey, pubJwk)
         .then(setSharedKey)
         .catch(() => setSharedKey('error'));
+      // Fingerprint des Partner-Keys berechnen (aus dem auf dem Server gespeicherten Public Key)
+      crypto.subtle.importKey('jwk', pubJwk, { name:'X25519' }, true, [])
+        .then(k => getFingerprint({ publicKey: k }))
+        .then(setPartnerFp)
+        .catch(() => setPartnerFp('?'));
     } catch {
       setSharedKey('error');
     }
@@ -241,10 +249,21 @@ export default function Nachrichten({ toast, mobile }) {
                     whiteSpace:'nowrap', overflow:'hidden', textOverflow:'ellipsis' }}>
                     {activeUser.username}
                   </div>
-                  <div style={{ color: sharedKey === 'error' ? '#ff6b9d' : 'rgba(78,205,196,0.5)',
-                    fontSize:8, fontFamily:'monospace', letterSpacing:1.5, marginTop:1 }}>
-                    {sharedKey === 'error' ? '⚠ SCHLÜSSEL INKOMPATIBEL' : '🔒 E2E VERSCHLÜSSELT · X25519 + AES-256-GCM'}
-                  </div>
+                  {sharedKey === 'error' ? (
+                    <div style={{ color:'#ff6b9d', fontSize:8, fontFamily:'monospace', letterSpacing:1.5, marginTop:1 }}>
+                      ⚠ SCHLÜSSEL INKOMPATIBEL
+                    </div>
+                  ) : partnerFp ? (
+                    <div title={`Fingerprint von ${activeUser.username} – vergleiche mit dessen Anzeige unter Einstellungen → Sicherheit`}
+                      style={{ color:'rgba(78,205,196,0.55)', fontSize:8, fontFamily:'monospace', letterSpacing:1, marginTop:2,
+                        cursor:'help', whiteSpace:'nowrap', overflow:'hidden', textOverflow:'ellipsis' }}>
+                      🔒 {partnerFp}
+                    </div>
+                  ) : (
+                    <div style={{ color:'rgba(78,205,196,0.35)', fontSize:8, fontFamily:'monospace', letterSpacing:1.5, marginTop:1 }}>
+                      🔒 E2E VERSCHLÜSSELT · X25519 + AES-256-GCM
+                    </div>
+                  )}
                 </div>
                 <button onClick={deleteConversation} style={{ ...S.btn('#ff6b9d', true), fontSize:10, flexShrink:0 }}>
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