From the NewScientist Tech section:
A technique for cracking computer passwords using inexpensive off-the-shelf computer graphics hardware is causing a stir in the computer security community.
Elcomsoft, a software company based in Moscow, Russia, has filed a US patent for the technique. It takes advantage of the “massively parallel processing” capabilities of a graphics processing unit (GPU) – the processor normally used to produce realistic graphics for video games.
Using an $800 graphics card from nVidia called the GeForce 8800 Ultra, Elcomsoft increased the speed of its password cracking by a factor of 25, according to the company’s CEO, Vladimir Katalov.
The toughest passwords, including those used to log in to a Windows Vista computer, would normally take months of continuous computer processing time to crack using a computer’s central processing unit (CPU). By harnessing a $150 GPU – less powerful than the nVidia 8800 card – Elcomsoft says they can cracked in just three to five days. Less complex passwords can be retrieved in minutes, rather than hours or days.