关键词: Piccolo结构, 差分密码分析, 线性密码分析

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