Multi-User Nonlinear Optical Cryptosystem Based on Polar Decomposition and Fractional Vortex Speckle Patterns

In this paper, we propose a new multiuser nonlinear optical cryptosystem using fractional-order vortex speckle (FOVS) patterns as security keys. conventional cryptosystems, mostly random phase masks are used the keys which prone to various attacks such brute force attack. current study, FOVSs generated optically by scattering of beam, known for azimuthal and helical wavefronts, through ground glass diffuser. have remarkable property that makes them almost impossible replicate. input plane, amplitude image is first encoded then modulated with FOVS mask obtain complex image. This further processed encrypted proposed method. Two private obtained polar decomposition enables multi-user capability in cryptosystem. The robustness method tested against existing contamination attack known-plaintext Numerical simulations confirm validity feasibility