Improved Linear (hull) Cryptanalysis of Round-reduced Versions of SIMON.
Danping Shi, Lei Hu, Siwei Sun, Ling Song, Kexin Qiao, Xiaoshuang Ma · IACR Cryptology ePrint Archive · 2014
SIMON is a family of lightweight block ciphers designed by the U.S. National Security Agency (NSA) that has attracted much at- tention since its publication in 2013. In this paper, we thoroughly in- vestigate the properties of linear approximations of the bitwise AND operation with dependent input bits. By using a Mixed-integer Linear Programming based technique presented in Aasicrypt 2014 for automatic search for characteristics, we obtain improved linear characteristics for several versions of the SIMON family. Moreover, by employing a recent- ly published method for automatic enumeration of dierential and linear characteristics by Sun et. al., we present an improved linear hull analysis of some versions of the SIMON family, which are the best results for linear cryptanalysis of SIMON published so far. Specically,