SNAKE(2)算法新的Square攻击

New Square Attack on SNAKE(2)

重新评估了分组密码SNAKE(2)算法抵抗Square攻击的能力。指出文献[4]中给出的基于等价结构的错误5轮Square区分器。综合利用算法原结构与其等价结构,给出了一个新的6轮Square区分器。利用新的区分器,对不同轮数的SNAKE(2)算法应用了Square攻击来恢复部分等价密钥信息,7轮、8轮、9轮SNAKE(2)算法的Square攻击时间复杂度分别为212.19、221.59、230.41次加密运算,数据复杂度分别为29、29.59、210选择明文。攻击结果优于文献[4]中给出的Square攻击。

The security of block cipher SNAKE （2） against Square attacks was re-evaluated.The wrong 5-round Square distinguisher based on equivalent structure given in paper [4] was pointed out.A new 6-round Square distinguisher based on both the structure of SNAKE （2） and its equivalent structures was proposed.Using the new 6-round Square distinguisher,Square attack was applied to 7,8,9-round SNAKE（2） to recover some information of the equivalent key.The time complexities are 212.19,221.59,230.41 respectively,and the data complexities are 29,29.59,210 respectively.The results are better than the Square attack given by paper[4].