In December 2008, an MD5 chosen-prefix collision attack was performed on a PlayStation 3 cluster to create a rogue CA certificate. A new implementation of this attack has been researched and developped to run an order of magnitude faster and more efficiently on video card GPUs, which now makes the attack practical to anybody. Software techniques to achieve the breakthrough performance gain will be demonstrated.
http://www.blackhat.com/html/bh-usa-09/bh-usa-09-speakers.html#Bevand
