MD5 To Be Considered Harmful Someday (21c3)

Joux and Wang’s multicollision attack has yielded collisions for several one-way hash algorithms. Of these, MD5 is the most problematic due to its heavy deployment, but there exists a perception that the flaws identified have no applied implications. We show that the appendability of Merkle-Damgard allows us to add any payload to the proof-of-concept hashes released by Wang et al. about this event: http://www.ccc.de/congress/2004/fahrplan/event/308.en.html