改进的MD4有意义碰撞攻击

摘要

在FSE 1996上,Hans Dobbertin给出了一个基于ASCⅡ编码且前20个字符是随机字符的有意义的MD4碰撞.贾珂婷和王小云教授于2009年给出了一个基于Latin-1字符集的有意义的MD4碰撞.以王小云教授的模差分方法为基础,采用于红波等在CANS 2005上给出的碰撞路线,给出了两个有意义的MD4碰撞实例,其中一个是基于GBK编码的汉语的有意义碰撞,另一个是基于UTF-8编码的英语的有意义的碰撞.同时给出了一个python脚本被篡改的实例.%In FSE'1996,Hans Dobbertin gave a meaningful collision on MD4 based on ASCⅡ,which contains meaningless words at the beginning of the text.In 2009,Jia and Wang presented a meaningful collision on MD4 based on Latin-1 character set,which contains meaningless words at the end of the text.In this paper,based on the modular differential method proposed by Wang,we gave two concrete meaningful collisions by using the differential characteristic proposed by Yu et al.in CANS 2005.One example of the meaningful collision is in Chinese and based on GBK,an other example is in English and based on UTF-8.Moreover,an example of tampered python script was proposed.