基于混沌系统的S盒生成算法的研究*

S盒是分组密码算法中唯一的非线性部件，设计一个性能良好的S盒具有重要的实际意义。本文提出了一种新的S盒构造方法，算法中利用两个混沌系统进行迭代，操作简单却大大增加了置乱效果。文中分析了S盒的密码学性能，包括双射特性，非线性度，严格雪崩准则，输出比特间独立性，差分概率和线性概率，最后在我们提出的S盒的Lyapunov指数定义的基础上，计算了本文构造的S盒的Lyapunov指数，结果表明该方法生成的S盒具有良好的密码学性质。

Algorithm research of generating S-box based on chaotic system

S-box is the only nonlinear component of block cipher algorithm. It is important to design S-boxes which have good cryptographic properties. This paper proposed a new method to generate S-box dynamically by iterating chaotic map several times. The algorithm used two chaotic systems in iterating, greatly increasing the scrambling effect. It analyzed the nonlinear and differential probability and calculated the Lyapunov exponent of the S-box. The analyze results show that the S-box has strong abilities on resisting attacks compared with other published S-box.