Double image encryption system based on principles of interference

In this paper a novel virtual optical encryption system was proposed. With the new system two images could be hidden in the three random phase plates. First of all, the two original images were encoded into the amplitude and phase of a complex signal, then the complex signal was transformed into stationary random white noise by using digital holography with the reference wave that generated by random phase plate. Then the white noise was further hided in two random phase plates by using the interference principle. The encryption algorithm for this new method was quite simple and did not require iterative operation. Simulation results prove the encryption effects. The influences of additive parameters on the decryption results are studied, and it is found that the encryption system is highly sensitive to these additive parameters, and the security of the system is further improved.