Spread spectrum characteristics of CGH for double random phase encrypted image

In this paper, a method for image optical encryption based on computer-generated hologram (CGH) theory combined with the 4f double random phase encryption system is proposed. The spread spectrum characteristics of the encrypted image recorded by CGH are analyzed. Due to the spread spectrum characteristics of spectral of CGH encrypted images in decryption process, this method enhances encryption security and flexibility, all principles and results are simulated by computer.