Multiple-image encryption based on authenticable phase and phase retrieval under structured light illumination

In this paper, a multiple -image encryption method is proposed based on authenticable phase and phase retrieval under structured light illumination. In the encryption process, each plaintext image is firstly encrypted into two phase masks by using phase retrieval algorithm under structured light illumination with the help of encryption authenticable phase, and then the final ciphertext is generated by using phase mask multiplexing technology, overcoming the trade-off relationship between encryption capacity and decryption quality, thereby the decryption quality is improved meanwhile the encryption capacity is expanded. Furthermore, the optical parameters of structured phase mask in the structured light illumination are introduced as supplementary digital keys, expanding the key space and enhancing the security of encryption method. In the decryption process, the decryption authenticable phase needs to pass authentication before it is used to decrypt the ciphertext, leading to a further improvement for the level of security of encryption method. Numerical simulations are performed to demonstrate the feasibility of the proposed multiple -image encryption method, and the simulation results show that the proposed method exhibits high feasibility and security as well as strong robustness and large capacity.