A Low-Complexity Key-Recovery Attack on 6-Round Midori64  

作　　者：XIE Xiaofeng TIAN Tian 

机构地区：[1]Information Engineering University,Zhengzhou 450001,China

出　　处：《Journal of Systems Science & Complexity》2023年第4期1738-1756,共19页系统科学与复杂性学报（英文版）

摘　　要：In EUROCRYPT 2017,a new structure-difference property,say“a-multiple-of-8”was proposed on 5-round AES.Inspired by the idea,yoyo attacks and mixture differential attacks were proposed yielding new records on data and computational complexities for key-recovery attacks against 5-round AES.In this paper,the authors attempt to apply the idea of mixture differential cryptanalysis to Midori64.Midori is a lightweight block cipher proposed at ASIACRYPT 2015.Although the structure of Midori is similar to AES,the MixColumn matrix of Midori is not MDS.Based on this observation,the authors present a class of deterministic differential trails on 2-round Midori.Then combined with the yoyo trick,a new type of 4-round retracing boomerang distinguishers is obtained on Midori.Based on the new 4-round distinguishers,a key-recovery attack on 6-round Midori64 is given that requires only 2^(27)computational complexity,2^(29)chosen plaintexts,2^(20)adaptively chosen ciphertexts.The key-recovery attack has been experimentally verified.

关 键 词：Boomerang attack Midori mixture differential attack yoyo attack 

分 类 号：TN918.4[电子电信—通信与信息系统]