- Add @ to swapkey, to disable it in classification

- Modify key Compromise for protocols that contain a timestamp to make the
  key compromise disclose a timestamp with a different type, namely 
  ExpiredTimeStamp so that they will not be accepted as timestamps in a new
  session, thereby simulating that they are expired.

spdl/SPORE/denning-sacco-lowe.spdl

@@ -14,6 +14,7 @@
 usertype Key;
 usertype SessionKey;
 usertype TimeStamp;
+usertype ExpiredTimeStamp;
 secret k: Function;
 usertype PseudoFunction;
 const dec: PseudoFunction;
@@ -27,7 +28,7 @@ protocol denningSaccoLoweSessionKeyCompromise(C)
     role C {
         const Ni,Nr: Nonce;
         const Kir: SessionKey;
-        const T: TimeStamp;
+        const T: ExpiredTimeStamp;
         var I,R,S: Agent;
 
         read_C1(C,C,    I,R,S);