Image encryption application in a system for compounding self-excited and hidden attractors

Abstract

Abstract Nowadays, chaos-based encryption systems implemented by hardware attracted highly attention. While chaotic systems, encryption algorithms and hardware platform are the core of the chaos-based image encryption system. In this paper, an image encryption system is developed. The proposed image encryption scheme employs a multi-scroll chaotic system and the Arnold map as entropy sources. The images are preprocessed by XOR operation between chaotic sequences and image pixels; Arnold map is used to change the position of the processed image pixels for scrambling the image. The chaotic sequences are generated by the multi-scroll chaotic system which is constructed by introducing Piecewise (PW) functions into Lorenz-like system. The modified Lorenz-like system produces a novel composite chaotic attractor consisting of a pair of different magnitude self-excited attractors and a pair of different magnitude hidden attractors. Through adjusting the parameters of PW functions, the system can also produce novel grid multi-scroll attractors. The hardware implementation of the image encryption scheme has been realized by using FPGA XC7A35TCPG236 and VGA monitor. The proposed encryption system consumes low power (248 mW) and has high throughput (4 bit/us) with an encryption time of 237 ms for encrypting a 256 × 256 plain image. Then, some basically tests are proved our image encryption system effectively.