MD5差分和差分路径的自动化构造算法

The Automatic Algorithm to Construct Difference and Differential Path in MD5

为了得到较好的差分,差分路径和充分条件,考察了MD5算法和差分攻击算法的原理,给出并证明了循环移位差分四种情况的概率,提出了MD5差分路径和充分条件的自动化构造算法,将构造差分和构造差分路径相结合,调整了搜索步长,提高了构造的成功概率。试验结果表明:得出的新差分路径重量为50,所需充分条件为272。

For Finding good difference,differential path and sufficient conditions,the theory of MD5 and differential attack algorithm were analyzed,four probabilities of circle shifting difference were proved,and the automatic algorithm to construct difference and differential path in MD5 were proposed.By combining the construction of difference with differential path and modifying the length of searching step,the successful probability of construction was promoted.Experiments showed that this differential path＇s HW is 50,and 272 sufficient conditions is needed.