Optical Encryption using Unequal Modulus Decomposition and Diffractive Imaging in Fresnel Domain

Abstract

In this paper, a secured cryptosystem based on diffractive imaging encoding and unequal modulus decomposition by using double random phase encoding in Fresnel domain is proposed. First, an input image is encoded using random phase masks and then intensity patterns are generated and after that the resultant is decomposed in two independent phase masks with unequal modulus. Here, unequal decomposition is used for creating one-way effective trapdoor function. As a result, the proposed scheme provide resistance to basic and specific attack proposed by Wang et.al. Numerical simulations are done to demonstrate the validity, feasibility and robustness of the proposed scheme.