Abstract:

To evaluate the security of Piccolo structure, the security against differential and linear cryptanalysis is investigated. A new lower bound on number of active round function and active S-boxes for arbitrary round differential characteristics is given. Using the duality between differential characteristics and linear approximations of Piccolo structure, the new lower bound on number of active round function and active S-boxes for arbitrary round linear approximations is also given. The authors prove that these lower bounds cannot be improved.

Key words: Piccolo structure, differential cryptanalysis, linear cryptanalysis

摘要：

为评估Piccolo结构的密码性能, 对该结构抵抗差分密码分析和线性密码分析的能力进行研究。给出任意轮差分特征中活动轮函数和活动S盒个数的一个新的下界, 并利用Piccolo结构的差分线性对偶性, 给出任意轮线性逼近中活动轮函数和活动S盒个数的一个新的下界。同时, 证明这些下界是不可改进的。

关键词: Piccolo结构, 差分密码分析, 线性密码分析