Asymmetric cryptosystem using QZ modulation with SPM in Fresnel domain

In this paper, we have introduced a new cryptosystem based on QZ modulation with structured phase mask (SPM) in Fresnel domain. For encryption using QZ decomposition, a plaintext image and RPM has been taken as inputs to give two upper quasitriangular matrices and two unitary matrices to give decryption key. SPM and Fresnel parameters also provide the addition keys to increase the key space. Simulation results are provided to show the effectiveness and strength of the proposed cryptosystem.