Enhancing the kinetic complexity of 2-D digital coupled chaotic lattice

Abstract

A 2-dimensional coupled logistic map lattice model and a 2-dimensional Logistic-nested-Sine map are proposed in this paper. In order to strengthen complexity of 2-dimensional coupled logistic map lattice, chaotic sequences are transformed to binary sequences, and new decimal sequences are constructed by perturbed binary sequences. Numerical experimental results demonstrate that this method can increase the complexity and ergodicity of 2-dimensional coupled logistic map lattice effectively. The initial values of the 2-dimensional coupled logistic map lattice are determined by utilization of the SHA 512 hash function. The row and column positions of pixels are shuffled completely in permutation process. Unlike 1-dimensional linear diffusion operation, we have adopted two-dimensional space diffusion began from random semi-surround. Keys security, correlation coefficient, information entropy, and ability of defending differential attack are analyzed to confirm the security of our encryption scheme. Experimental results confirm that the proposed algorithm can encrypt image effectively.