Optical Image Encryption Based on Joint Fresnel Transform Correlator

Optical verification systems can make image hide in high-security phase key through the phase retrieval operation Conventionally, optical verification systems based on the joint transform correlator usually use Fourier transform. In this paper we propose the joint Fresnel transform architecture and use the methods of the projection onto constraint set and nonlinear transform to determine the pure phase key. As shown in our simulation results, the advantages of the proposed method include that our system is lensless and the additional wavelength and distance parameters enhance the system security.