Optical encryption of gray image based on the fourier computer generated hologram and logical modulation

In this paper, we proposed a novel optical encryption and decryption method of gray image based on the Fourier computer-generated hologram (CGH) and logical modulation. Since the encryption method using the CGH or the logical modulation alone has a shortness of low security, the proposed novel encryption combines the two methods together. In our encryption processing, the hologram, which is gotten by Fourier transform from the original image, is encrypted by logical modulation with the chaotic sequence. Simulation results and analysis show that the security and robustness of the proposed approach has a satisfactory performance.