A Novel Method for Designing Dynamical Key-Dependent S-Boxes based on Hyperchaotic System

The substitution box (S-box) is found in many block cipher, and it is a very important component. Since the chaotic system has several significant advantageous properties desirable for cryptosystem, the design of S-box using chaos has attracted a great deal of attention in recent years. In this paper, a novel method for designing key-dependent S-boxes based on a four-dimensional hyperchaotic Chen system has been presented. The design process for constructing S-boxes is described in detail and the results of numerical analysis indicate that all the criteria for S-boxes including bijection, nonlinearity, SAC, BIC and differential approximation probability can be fulfilled. Furthermore, the S-box’s sensitivity to the secret key is also conducted. All the results in this paper have shown that the presented method is a good candidate for designing dynamical S-boxes that can be widely used in block cipher.