Efficient and secure cryptosystem for fingerprint images in wavelet domain

In this paper, a fingerprint image encryption algorithm is proposed in order to enhance the protection of fingerprint-based systems against replay attacks. The proposed algorithm is consisting of permutation and diffusion operations in wavelet domain, whereas, one-level Lifting Wavelet Transform Integer-to-Integer is performed to the original fingerprint image. The approximation and detail sub-bands are then partitioned into blocks and permuted using a permutation key. It is noteworthy that, for each sub-band the Rubik's cube principle is applied. The encrypted image is constructed by ordering the encrypted sub-bands. Eventually, an experimental tests and security analysis were conducted on three fingerprint images attained through Fingerprint Verification Competition "FVC 2000" database. The obtained results confirm the effectiveness of the proposed encryption algorithm and clearly show the robustness against common attacks, for example differential and statistical attacks. In addition, it reveals the high security level achieved.