Substitution-box Generator Based on Chaotic Linear Feedback Shift Register

Abstract

The most basic principle of providing cryptographic security is to trans-form the original data into a form that the attacker cannot understand. A replacement/permutation architecture was developed to meet this princi-ple by Shannon, one of the leading figures in information theory. This architecture, known as substitution-box/S-Box, has become the most fun-damental component of block cipher algorithms. Since these components have a nonlinear structure, they directly affect the success of differential cryptanalysis. There are various alternatives for S-Boxes. Mathematical-based transformations from these alternatives are used in the AES algo-rithm, which is accepted as the modern encryption standard. However, since such sboxes are vulnerable to side channel attacks, alternative de-sign approaches are being investigated. Studies have shown that random selection based s-boxes are an alternative to other design techniques. In this study, it has been shown that chaos-based s-box structures can be produced using an innovative entropy source. The performance analyzes of the produced s-boxes were carried out on five basic metrics and it was seen that they could be an alternative to the existing structures. It has been evaluated that the s-boxes we produce can be used in many encryp-tion algorithms in the future.