基于Feistel结构的分组密码算法Eslice

一族安全性较高的分组密码算法Eslice,包含3个版本:Eslice-64-64,分组长度和密钥长度均为64比特;Eslice-64-128,分组长度为64比特,密钥长度为128比特;Eslice-128-128,分组长度和密钥长度均为128比特。Eslice的设计灵感源于LBlock。整体采用Feistel结构,轮函数采用SP结构,所选取的S盒其各项密码性质均达到最优。线性变换仅有循环移位和异或两种操作,且密钥生成算法与加密算法使用相同的S盒。进一步,分析Eslice针对差分、线性、积分等密码分析方法的安全性,利用基于混合整数线性规划(MILP)的搜索模型,得到20轮的最小活跃S盒的个数为41个,比LBlock 20轮的最小活跃S盒的个数少3个,通过活跃S盒的个数估算差分概率和线性偏差,对算法进行安全性评估。结果表明,Eslice算法可以有效的抵抗差分攻击和线性攻击。

Block cipher algorithm Eslice based on Feistel structure

A family of highly secure block cipher algorithms Eslice, including three versions: Eslice-64-64, the block length and key length are both 64 bits; Eslice-64-128, the block length is 64 bits, and the key length is 128 bits; Eslice-128-128, the block length and key length are both 128 bits. Eslices design was inspired by LBlock. The Feistel structure is adopted as a whole, and the SP structure is used for the round function. The selected S-box have all the optimal cryptographic properties. The linear transformation has only two operations: cyclic shift and XOR, and the key generation algorithm and the encryption algorithm use the same S-box. Furthermore, the security of Eslice for differential, linear, integral and other cryptanalysis methods is analyzed. The search model based on Mixed Integer Linear Programming(MILP)are used, and the number of minimum active boxes in 20 rounds is 41, which is 3 less than that of LBlock in 20 rounds. The differential probability and linear deviation are estimated by the number of active boxes, and the security of the algorithm is evaluated. The results show that Eslice can effectively resist differential attack and linear attack.