The Design of dynamical S-boxes based on discrete chaos map system

This paper presents a method for obtaining dynamically cryptographically strong substitution boxes (S-boxes) based on discrete chaos map system (DCMS). The cryptographical properties such as bijection, nonlinearity, strict avalanche, output bits independence and equiprobable input/output XOR distribution of these S-boxes are analyzed in detail. The results of numerical analysis show that all the criteria for designing good S-box can be satisfied approximately. As a result, our approach is suitable for practical application in designing block cryptosystem.