Optical color image encryption based on chaotic fingerprint phase mask in various domains and comparative analysis

Random phase masks serve as secret keys and play a vital role in double random phase encoding architecture. In this paper, we propose a new, to the best of our knowledge, method to generate the random phase masks using the chaotic Henon map and fingerprint. We then extend the generated chaotic fingerprint phase masks to the Fourier transform domain, fractional Fourier transform domain, Fresnel transform domain, and Gyrator transform domain to encrypt color images. In these four color image encryption schemes, the fingerprint and chaotic parameters serve as secret keys directly, and the chaotic fingerprint phase masks are just used as interim variables and functions. If the sender and receiver share the fingerprint, only the chaotic parameters are needed to transmit over the network. Thus, the management and transmission of the secret keys in these four encryption schemes are convenient. In addition, the fingerprint keys which are strongly linked with the sender or receiver can enhance the security of these four encryption schemes greatly. Extensive numerical simulations have been carried out to verify the feasibility, security, and robustness of these four color image encryption schemes.