Optical image encryption based on chaotic fingerprint phase mask and pattern-illuminated Fourier ptychography

Abstract An optical image encryption scheme based on chaotic fingerprint phase masks (CFPMs) and pattern-illuminated Fourier ptychography (FP) is proposed. During the encryption process, the primary image that is under the non-uniform intensity patterns’ illumination can be encrypted into multiple low-resolution intensity images with the CFPMs placed respectively at the input plane and the Fourier plane. And during the decryption process, the primary image can be recovered from these encrypted images with a Fourier ptychographic recovery algorithm and CFPMs. In this proposed image encryption scheme, the fingerprint image and the chaotic parameters are served as secret keys directly, and the CFPMs are just used as interim variables and functions. If the fingerprint image is shared by the sender and the authorized receiver, the security of the proposed image encryption scheme will be enhanced greatly, and the management and transmission of the secret keys will also become convenient to some extent. Additionally, the illumination pattern can also act as an additional secret key. Numerical simulations have been performed to verify the feasibility, security and robustness of the proposed image encryption scheme.