A Novel Biometric Cryptosystem using LDPC and SHA based Iris Recognition

We use Low Density Parity Check (LDPC) error correction code to solve fuzziness i.e., the variability and noise in iris code generated from Iris Recognition System (IRS) and Secure Hash Algorithm (SHA-512) to transform unique iris code into hash string to make them as a Cancellable Biometric. SHA-512 hash string is used as a key for 512 bits Advanced Encryption Standard (AES) encryption process. In the decryption process, Hash comparison is made between new hash generated by SHA-512 from error corrected iris code and hash stored in smart card. If authentic, 512 bits AES decryption is accomplished. Experiments indicate that, use of LDPC code results in better separation between genuine and impostor users which improves the performance of this novel cryptosystem. Security of this system is very high, which is 2 under birthday attack. AES algorithm is enhanced by using 512 bits key and increasing the number of rounds. General Terms Iris Pattern Recognition, Cryptography, Computer Security.