Feistel-SP结构迭代差分的自动化搜索

Automated search of iterative differential mode with feistel-SP structure

基于新的符号差分表示方法提出了一种自动化搜索技术,可以搜索出典型Feistel-SP结构的分组密码的最优迭代差分模式,选择合适的迭代差分模式可以遍历出所有最优的迭代差分路径,不仅大大降低计算复杂性,还能通过迭代差分模式构造出多轮最优差分路径。以轻量级分组密码MIBS为例,应用自动化搜索工具,给出了MIBS的3轮、4轮最优迭代差分路径,概率分别为2-20、2-26,并搜索出所有满足条件的最优迭代差分路径。

Based on a new symbol differential representation,an automated search technique is presented,which can search out the optimal iterative differential mode of the block cipher with Feistel-SP structure.Selection of an appropriate mode can help find out all of the best iterative differential paths.The proposed method can not only greatly reduce the computational complexity,but also construct several rounds of optimal differential paths and find other unknown results.Based on the lightweight block cipher MIBS with automated search tools,the third and fourth optimaliterative differential paths of MIBS are found out,and the probabilities are 2-20 and 2-26 respectively.In addition,all the optimal iterative differential paths that meet the conditions are searched out.