Something more secure, eh? Have your applet register w/ the server using a random number, something 1 out of very large. The server would generate a unique key that when presented, will show the answer only to the person that presents the same large number and unique key.

The large number represents a who-am-i. You can use IPs, but you then have to worry about people who nat, or are on load balancers. Acts like a cookie to present to the server.

They key would act much like your key. Something that's one time use, and only hackable if you hack the client. Nothing that would be easily guessable by checking urls. (Imagine if your key=answer).

Update: Collisions should be rare if you append say, the ip to the random number.