Image Encryption via Base-n PRNGs and Parallel Base-n S-Boxes

Abstract

The fast-paced advancement in multimedia production and exchanges over unsecured networks have led to a dire need to develop security applications. In this regard, chaos theory has much to offer, especially high-dimensional (HD) chaotic functions of fractional order. The authors propose a new symmetric, secure and robust image encryption method in this research work. In this method, the authors hybridize the Chen and Chua chaotic functions with a Memristor circuit to benefit from the strengths of each. Such a hybridization of systems allows for the generation of pseudo-random numbers which are used to develop encryption keys and substitution boxes (S-boxes). For the application of the generated encryption keys towards carrying out data diffusion, instead of the most commonly used approach of bit-stream level XOR , this work utilizes different logical and arithmetic operations, which is made possible by performing this process over variable numerical bases. Moreover, multiple S-boxes of varying base- n are generated and utilized in a parallel fashion, carrying out data confusion. The computed numerical results reflect the superior capabilities of the proposed image encryption technique, signifying resilience and robustness against various attacks.