Image Encryption via Base-<i>n</i> PRNGs and Parallel Base-<i>n</i> S-Boxes

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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">XOR</i> , 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- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> 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.