一种基于离散混沌系统的S-Box候选算法设计

S-Box是现行分组密码中唯一的非线性部件,主要提供了分组密码算法中必需的混淆作用,其密码强度决定了整个分组密码的安全强度。为进一步提高S-Box的强度,结合离散混沌系统的内在随机性、有界性、非周期性及对初始条件和参数极度敏感等特点,提出一种采用多混沌映射和交叉映射生成S-Box的生成算法。实验分析表明,该算法生成的样本密钥敏感性强,随机性好,既能较好地满足S-Box设计所要求的各项准则和特性,安全性高,同时又能降低计算复杂度,提高计算速度,且易于生成和扩展,因而是一种性能良好的S-Box候选算法。

Design of S-Boxes based on discrete chaos system

S-box is the only nonlinear components of block cipher algorithm which can provide confounding effect. Its password strength determinates the security strength of the whole cipher algorithms. An S-Box generation algorithm based on the discrete chaos system which uses multi-chaos maps and cross-generation method to generate S-Boxes was proposed. Good characteristics such as bounded, aperiodic and extremely sensitive to initial conditions and parameters of discrete chaos system were combined in the algorithm. Experimental analysis shows that the samples generated by our algorithm have strong key sensitivity and good randomness, thus can satisfy both the high security criteria and features required by the S-Box design. It improves the performance by reducing the computational complexity and has good scalability and low implementation cost. Therefore, the proposed method can serve as a promising choice for designing S-Boxes.