With the increasing reliance on electronic information, which needs to be exchanged across the internet or stored on open networks, cryptography is becoming an increasingly important feature of computer security. A biometric key dependent
cryptosystem is proposed, to ensure the security of the whole system by using iris pattern as a key in a cryptosystem, like, Key-dependent Advanced Encryption Standard (KAES). KAES is used to ensure that no trapdoor is present in cipher and to expand the key-space to slow down attacks. The proposed system gave significant results under various tests for the key uniqueness and the system randomness.