Color Image Encryption Based on 2D Hyperchaotic Sine Couple Map and Block Scrambling

Abstract

In this paper, we propose a novel 2D hyperchaotic Sine couple map (2D-HSCM) and then the proposed 2D map is analyzed using bifurcation diagrams, attractor trajectory, Lyapunov exponent, fixed point, sample entropy, symmetry, dissipative, etc. To prove the availability of the chaotic system, we also implement the 2D-HSCM on FPGA platform. Based on the 2D-HSCM, we propose a novel image encryption algorithm called the HSCM-IEA. In the HSCM-IEA, there are many operations that mainly contain block scrambling and modular diffusion. Block scrambling is divided into intra-block pixel scrambling and inter-block relationship scrambling. In the intra-block pixel scrambling, the longest increasing subsequence (LIS) is employed as the index for the row and column cyclic permutations. In the inter-block relationship scrambling, we use the flip to disrupt the relationship between each block. After block scrambling, the encrypted image is obtained by the modulo operation. To verify the outperformance of the HSCM-IEA, we conduct the experiments contain experimental simulation, statistical analysis, security analysis and speed analysis. The results demonstrate that the proposed algorithm can obtain the visually meaningless cipher. Besides, not only does the HSCM-IEA have the ability to generate a more security cipher, but also can reach a high efficiency compared with some existing image encryption algorithms.

Keywords

• Hyperchaotic map
• image encryption
• longest increasing subsequence (LIS)