Characteristic analysis of encryption and decryption in random polarization optical encryption algorithm

To demonstrate the function of random polarization mask in an optical encryption system, the influence of parameters in random polarization mask on encryption effect and decryption error in double random polarization optical encoding system was analyzed by means of theoretical analysis and numerical simulation. The different effects of random phase encoding algorithm and random polarization encoding algorithm on encryption effect and decryption error were compared and presented. The results indicate that a satisfying white-noise liked encrypted image can be obtained when using random phase mask or random polarization mask. But a larger key space is observed with random polarization mask due to its two structured parameters. From decryption point of view, the key sensitivities are different among the different parameters in random polarization mask or random phase mask. The random polarization encoding algorithm has the favorable feasibility for practical application. The results are significant not only for the understanding on the intrinsic of random phase and polarization optical encoding system but also for the design of optical encryption system with high security level.