Globally Coupled Private Image Encryption Algorithm Based on Infinite Interval Spatiotemporal Chaotic System

This article proposes a new infinite parameter range spatiotemporal chaotic system named improved sinusoidal dynamic non-adjacent coupled mapping lattice (ISDNCML). The system performance test shows that ISDNCML has more random lattice interaction, better chaos and excellent cryptography. Based on the characteristics of ISDNCML, the globally coupled private image encryption algorithm is proposed. The algorithm first identifies the private area of an image and then couples the private and non-private areas for encryption. While coupling encryption, ill-conditioned dynamic diffusion is introduced into the private area, which avoids the repeated encryption of the private area on the premise of ensuring the security of private information. The security and practicability of this proposed cryptographic system are verified by the analysis of ISDNCML and various tests of encryption effect.