Chosen-prefix collisions for MD5 and applications

M.M.J. Stevens, A.K. Lenstra, B.M.M. Weger, de

Research output: Contribution to journalArticleAcademicpeer-review

22 Citations (Scopus)

Abstract

We present a novel, automated way to find differential paths for MD5. Its main application is in the construction of chosen-prefix collisions. We have shown how, at an approximate expected cost of 239 calls to the MD5 compression function, for any two chosen message prefixes P and P', suffixes S and S' can be constructed such that the concatenated values P||S and P'||S' collide under MD5. The practical attack potential of this construction of chosen-prefix collisions is of greater concern than the MD5-collisions that were published before. This is illustrated by a pair of MD5-based X.509 certificates one of which was signed by a commercial Certification Authority (CA) as a legitimate website certificate, while the other one is a certificate for a rogue CA that is entirely under our control (cf. http://www.win.tue.nl/hashclash/rogue-ca/). Other examples, such as MD5-colliding executables, are presented as well. More details can be found on http://www.win.tue.nl/hashclash/ChosenPrefixCollisions/.
Original languageEnglish
Pages (from-to)322-359
JournalInternational Journal of Applied Cryptography
Volume2
Issue number4
DOIs
Publication statusPublished - 2012

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