Double image encryption using 3D Lorenz chaotic system, 2D non-separable linear canonical transform and QR decomposition

Abstract

In this paper, a double image encryption scheme using 3D Lorenz chaotic system and QR decomposition in 2D non-separable linear canonical transform domain is proposed. Here the independent parameters of the 2D non-separable canonical transform enlarge the key-space of the proposed scheme and enhance robustness against brute-force attack. 3D Lorenz chaotic system is employed for creating a permutation keystream for pixel transaction process. The proposed scheme is non-linear and asymmetric in nature. To validate and verify the proposed cryptosystem, the numerical simulations have been performed on grayscale images. Results display that the proposed scheme has greater robustness to occlusion and special attacks.