Thanks JB ! Well what if I am crypting the user ids say from 1 to 100000 which are integers? I am using Crypt::DES crypt and decrypt methods. And I tried to test this using standard 8 byte text (11111111) it still returns sane encrypted string. My question is how will I get the different encrypted strings each time? To my understanding I need to change the salt that's why I tried to change Key, (But it fails :) sorry for half-hearted tweaking) Can you suggest what would be olution? Thanks LF