Access Log
Use a hash of the access log as an additional kind of password. The access log (Computer/Access Time/Access ID) is known to the client and the server. Intruders would need to listen and record the communication from the beginning.
Log Not Matching
There is an access log available, on the client and the server, but they don't match.
Lock Access
The access can be locked manually by the user or automatically, when the access logs of the client and the server don't match.
Explicit Unlock
/livcos.org/data/map/brainstorm/AccessSecurity