基于遗传算法的快速可重构S盒硬件设计

Hardware Design of Fast Reconfigurable S-box Based on Genetic Algorithm

传统S盒硬件结构只对应一种密码算法,密码硬件的灵活性和安全性差。本文通过分析大部分分组密码的特点,设计了一种可在相同硬件上重构实现4×4和6×4规格S盒的新电路结构。为了提高S盒硬件对不同密码算法的适应性,采用了硬件复用技术,且所设计的可重构S盒具有较快的重构速度和较好的扩展性;为了提高S盒的安全性,采用遗传算法对可重构S盒电路进行优化设计。在构造遗传算法的适应度函数时,重点考虑了影响S盒安全性的非线性度和差分均匀度。以4×4的S盒设计为例进行了实验,实验结果验证了可重构S盒的灵活性和安全性,证明了可重构S盒电路结构及优化设计方法的正确性。

With its disadvantages such as inflexibility and poor security, the traditional hardware structure of S-box can only be suitable for a cryptography algorithm. By analyzing the characteristics of most of the block ciphers, a new S-box circuit structure is designed, whose size can be reconfigured into 4×4 or 6×4 with same hardwares. To improve the adaptability of S- box to different cryptography algorithms, the hardware multiplexing technology is adopted, and the proposed reconfigurable S-box has a faster reconfiguration speed and better expansibility. To reinforce the security of S-box, genetic algorithm is adopted to optimize the reconfigurable S-box circuit. For the construction of the fitness function of genetic algorithm, nonlinearity and difference uniformity are mainly considered, which affect the security of S-box. Taking the 4×4 S-box for example, the experiment results verify the good flexibility and security of the reconfigurable S-box, and also check the correctness of the reconfigurable S-box circuit structure and the optimum design method.