diff --git a/messenger.py b/messenger.py
index d797b59..0b6ee95 100644
--- a/messenger.py
+++ b/messenger.py
@@ -40,8 +40,10 @@ class MessengerClient:
         return self.certificate
 
     def receiveCertificate(self, certificate, signature):
-        raise Exception("not implemented!")
-        return
+        self.server_signing_pk.verify(signature, certificate, ec.ECDSA(hashes.SHA256()))
+        name, public_bytes = pickle.loads(certificate)
+        public_key = ec.EllipticCurvePublicKey.from_encoded_point(CURVE, public_bytes)
+        self.certs[name] = public_key
 
     def sendMessage(self, name, message):
         raise Exception("not implemented!")