基于MILP搜索的ANU算法积分分析

ANU算法是由Bansod等人发表在SCN 2016上的一种超轻量级的Feistel结构的分组密码算法。截至目前,没有人提出针对该算法的积分攻击。为了研究ANU算法抗积分攻击的安全性,根据ANU算法的结构建立起基于比特可分性的MILP模型。对该模型进行求解,首次得到ANU算法的9轮积分区分器;利用搜索到的9轮区分器以及轮密钥之间的相关性,对128 bit密钥长度的ANU算法进行12轮密钥恢复攻击,能够恢复43 bit轮密钥。该攻击的数据复杂度为2^63.58个选择明文,时间复杂度为2^88.42次12轮算法加密,存储复杂度为2³³个存储单元。

Integral cryptanalysis on ANU based on MILP

ANU cipher,published on SCN 2016 by Bansod et al,is an ultra lightweight Feistel block cipher.There was no integral attack proposed against it yet.In order to study the resistance against integral analysis of ANU cipher,this paper established a MILP model based on bit-based division according to the structure of ANU cipher.By solving the model,it got the 9-round integral distinguisher of ANU for the first time.Based on the 9-round integral distinguisher and the correlation between round keys,it attacked 12-round ANU with 128 bit key size and could recover 43 bit round key.The data complexity of this attack is 2^63.58chosen plaintext,the time complexity is 2^88.42of 12-round encryption,and the storage complexity is 2³³.