Multiple-image encryption based on optical asymmetric key cryptosystem

We propose a multiple-image encryption scheme with asymmetric keys and demonstrate it by optical experiments. The original secret images are multiplexed and encoded into a real-valued ciphertext using only one public encryption key. In the decryption process, each secret image can only be de-multiplexed by its corresponding private decryption key. The multiplexing capacity is analyzed through examining the distribution of cross-talk noise and the key space of private decryption key. Numerical simulations and optical experiments have been carried out to demonstrate the validity, high security, and large multiplexing capacity of the proposed method.