A novel method of dynamic S-box design based on combined chaotic map and fitness function

Abstract

This paper introduces a method of generating a strong S-box by using combined chaotic system and fitness function. Our method presents an algorithm which has two stages: static S-box generation and dynamic S-box optimization. Chaotic sequences generation, sequences discretization are involved in the first stage. Moreover, the proposed static S-box is converted into a dynamic S-box with the help of fitness function. The optimal S-box satisfies the following criteria: bijectivity, nonlinearity, strict avalanche criteria, output bits independence criterion, equiprobable inputs/outputs XOR distribution. Extensive experiments demonstrate that the proposed algorithm has excellent performance in cryptography and attacks resistance.