Developer deploys graphics cards to accelerate password cracks

Nick Hawkesmoor

Nvidia's GeForce 8 series of graphics chips can be used to crack Windows NT LAN Manager (NTLM) passwords 25 times more quickly than was previously possible, security software developer Elcomsoft has claimed.

The Russia-based company this week announced the second major release of its Distributed Password Recovery application, a tool designed to recover forgotten or lost passwords for a wide range of application and document types, including PDP-protected ZIP files, Adobe Acrobat PDFs, Lotus Notes ID files and Microsoft Office documents.

Elcomsoft admits its software uses "brute force" to crack a file's password, thus exposing the lost key to the user. The technique essentially tries all possible password combinations until it finds the one that fits. It works, but it's time time-consuming.

"Using a modern dual-core PC you could test up to 10m passwords per second," Elcomsoft said, "and perform a complete analysis in two months."

But use a GeForce 8 series card and Nvidia's Compute Unified Device Architecture (CUDA) tools to run the cracking algorithms on the GPU rather than the CPU, and you can finish up in 3-5 days, the developer claimed.

"Since high-end PC mother boards can work with four separate video cards, the future is bright for even faster password recovery applications," it added.

CUDA was launched almost a year ago to enable scientists and engineers to use graphics cards typically aimed at gamers for more serious number-crunching applications. The GeForce 8 series of GPUs went on sale in March 2007.