An efficient image cryptosystem based on wolfram sequence and RNS

Abstract

In this paper we propose a novel encryption algorithm for digital images using the moduli set {2n+2, 2n+1, 2n}. The technique uses the Wolfram sequence for resizing, bitwise-XOR for pixel scrambling and modulus operation for pixel encoding. In the proposed scheme, a digital image is first segmented into many parts. A quarter (the upper most left part) of the segmented image is used to perform the scrambling and the modulus processes. Experimental results reveal that the proposed scheme can effectively encrypt/decrypt images with good compression ratio and a very minimal distortion. Simulation analyses also show that the scheme has a large key space, high information entropy, low correlation coefficient, highly sensitive to change in secret keys and efficient in both bit representation and internal memory requirement

Keywords: Moduli set, XOR operation, pixel scrambling, Wolfram sequence, encryption algorithm.