Optimize And Design S-box Based On PSO Algorithm

Modern Cryptography Theory and password technology is an important foundation for the field of information security. In the information age of today, with the development of networking and communication technology, more and more information transmitted over the network, information security and protection becomes increasingly important. Block cipher is an important branch of cryptography, it has features of easy to achieve standardization and ease of hardware and software, usually it is the core system in information and network security for data encryption, digital signature, authentication and key management. The S-box is the only non-linear components in block cipher, so its password strength determines the strength of block cipher security. It's difficult to obtain good global results using traditional mathematical methods. In recent years, intelligent optimization algorithm is effective in classic NP-C problem solving and has better overall performance. Currently, genetic algorithm is the more advanced method in S-box design. But it prone to premature and, therefore, affect its optimization. Because of PSO has memory, so you can avoid a good local optimum, can effectively reduce computational time. This article in-depth study of the inertia weight particle swarm algorithm, and used to solve the optimization problem S-box.This thesis presents the inertia weight particle swarm optimization S-box, avoid early PSO prone to premature and slow convergence of iterative problems later by adjusting the social factor, learning factor and inertia weight parameter is set, and according to different applications need to control the convergence rate of PSO, resulting in more accurate optimization results. The experimental design proved PSO can enhance the anti-S-box cryptanalysis, increase password strength, and can design a better performance of the S-boxes, and can significantly reduce the S box design time compared with genetic algorithm and increase design efficiency. Then S-box designed by the inertia weight particle swarm algorithm are applied to the field of image encryption, verify the design of S-boxes can be effectively used in the actual encryption of them, with good promotional value through explicit graph, graph the results of encryption, key sensitivity analysis, clear and encryption histogram graph comparing, the sensitivity analysis of several aspects.