Camellia算法中S盒的密码学性质

Cryptographic Properties of the Camellia S-box

作为大多数分组密码中唯一的非线性结构,S盒在很大程度上决定了分组密码的安全性。论文首先分析Camellia算法中S盒的迭代循环周期,然后从布尔函数出发,利用Walsh谱理论分析其平衡性、非线性性、严格雪崩准则、扩散特性和相关免疫性等密码性质,从理论上揭示了Camellia算法中S盒的安全性,最后指出了该算法中可能存在的安全隐患。

As the only nonlinear structures in most block ciphers, S-boxes determine toa great extent the block cipher＇s security. In the paper, we first analyse the overlap distributing periods of the Camellia S-box. Then, we take a deep look at the Camellia S-box from the angle of Boolean function with the theory of Walsh spectrum, and analyse the Camellia S-box characteristics such as balance, nonlinearity, strict avalanche criterion, propagation criteria and immunity. The security of the Camellia S-box is revealed theoretically. And finally we point out the hidden trouble existed in the algorithm.