Polarization encoded optical encryption enhanced with Radon transform

Abstract

We propose a robust polarization-based optical encryption scheme combining random degree of polarization (DOP) and state of polarization (SOP) masks. The encrypted and decrypted images obtained using SOP mask based on pixelated half waveplate and pixelated polarizer are compared with original image based on mean-square-error (MSE) and correlation coefficient (CC). The degrees of freedom of the encryption system are further increased with the Radon transformation of the target image and random amplitude key. We have used Stokes-Müller formalism for this scheme to realize it with physically measurable quantities. The outcomes of the individual encryption approaches based on SOP/DOP and combined (DOP, SOP, and Radon transform) are compared both qualitatively and quantitatively. The effects of Gaussian noise and occlusion attack on the proposed scheme are also analyzed. We anticipate that this research would yield a novel, readily implementable security-augmented optical encryption scheme.