A image encryption algorithm based on coexisting multi-attractors in a spherical chaotic system

In recent years, chaotic systems have been widely used in several engineering fields. In this paper, an image encryption algorithm for multi-attractor coexistence-spherical chaotic systems is proposed. Various dynamics of the spherical chaotic system are analyzed in detail to ensure that the system can produce a high complexity mask block with optimal parameters. The encryption algorithm consists of three main phases, image reconstruction, confusion and diffusion. In the reconstruction phase, the two-dimensional (2D) discrete cosine transform (DCT) is used to compress and reconstruct the image efficiently and eliminate image redundancy. In the obfuscation phase, use Logistic map to shuffle the image pixels of arbitrary size. In the diffusion stage, a mask sequence with high complexity is randomly selected based on the image information and the encryption date, and the scrambled image is subjected to add-and-take mode and cyclic shift diffusion operations. The experimental results and several security analyses show that the algorithm has a large enough key space. The ciphertext adjacent pixel correlation is almost zero. The number of pixel change rate (NPCR) is 99.6123% and the uniform average change intensity (UACI) is 33.4638%, which basically close to the theoretical values. The encryption speed is 30.327 ms and execution time is 69.151Mbps. The key sensitivity is strong, and the algorithm can effectively resist known plaintext and selective plaintext attacks, as well as shear and noise attacks. The encryption scheme has good encryption effect in terms of security and efficiency, and is very suitable for practical application.

Automated summary

This paper proposes an image encryption algorithm based on multi-attractor coexistence-spherical chaotic systems. By analyzing the dynamics of the spherical chaotic system, the algorithm ensures the generation of a high complexity mask block with optimal parameters. Experimental results and security analyses demonstrate that the algorithm has a large key space, can effectively resist various attacks, and has good encryption effect and efficiency.