Abstract
In general, Substitution box (S-box) is one of the components in the block cipher and plays an important role in the process of encryption. In this paper, an improved method is presented, which can obtain stronger S-boxes than the methods only based on chaos. Compared to the original method in [13], the proposed method is more efficient and can get more S-boxes with high cryptographic properties. Simulation tests show that the presented S-box has good cryptographic performance, which justifies that the improved algorithm is effective in generating strong S-boxes.