Your code works for me under Ubuntu with JDK1.7.0_21 so I suspect that you do not actually have the 'unlimited strength' files installed in the jdk/jre that is actually being used. Make sure that you are picking up the jdk/jre that you think you are and if you are make sure you have installed the 'unlimited strength' files correctly.
P.S. Turning cipher text into a
String using
is in general a sure way to corrupt it. OK you might get away with it for a particular ciphertext but in general you won't.