Generating Fast MD5 Collisions With ATI Video Cards

Posted by timothy on Saturday August 1, 2009 @07:33AM from the how-to-get-grants-for-game-hardware dept.

An anonymous reader writes "Yesterday at Black Hat USA 2009, a talk entitled MD5 Chosen-Prefix Collisions on GPUs (whitepaper) (Both PDFs) presented an implementation written in assembly language for ATI video cards that achieves 1.6 billion MD5 hash/sec, or 2.2 billion MD5 hash/sec with reversing, on an ATI Radeon HD 4850 X2. This is faster than the much-publicized 1.4-1.9 billion hash/sec figure that was supposedly reached on a PlayStation 3 by Nick Breese at Black Hat Europe 2008 (he later noticed an error in his benchmarking tool). Compared to the cluster of 215 PlayStation 3s that was used to create a rogue CA in December 2008, Marc Bevand claimed a cluster of 12 machines with 24 video cards would be a bit faster, consume 5 times less power, and be 10 times cheaper."

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Re:Sensible collissions that don't affect size? by Anonymous Coward · 2009-08-01 08:19 · Score: 5, Insightful

The attack that is mentioned in the story, the creation of the rogue CA certificate, is an example of a successful MD5 collision attack with a practical application. The "random" garbage was inserted in a part of the certificate signing request which is opaque to the certificate authority. That was also an example of a useful collision attack, so these are actually dangerous (not just pre-image attacks).