Optical Asymmetric Cryptosystem Based on Kronecker Product, Hybrid Phase Mask and Optical Vortex Phase Masks in the Phase Truncated Hybrid Transform Domain

This research work proposes a novel asymmetric scheme by utilizing the hybrid phase truncated fractional Fourier and Gyrator transform with the secure enhancement by adding Kronecker product as a key. In this cryptosystem, the encryption keys constitute Hybrid Phase Mask along with the Optical Vortex Phase Mask and Kronecker product as the other keys. The Hybrid Phase Mask is formed by the combination of a secondary image and random phase mask. The phase truncated parts during encryption process are reserved as decryption keys with the inverse Kronecker product. The proposed method comprises of more obscure keys for upgraded security and to defend different attacks. In support of the technique proposed, the results under the effect of various attacks are presented. The efficiency and robustness of the presented cryptosystem has been examined and demonstrated by simulation in MATLAB (R2014a) with different performance parameters.