Because of the computational power of today's GPUs, GPUs are starting to be harnessed more and more to help out CPUs with some hardcore number crunching. That is the concept behind Nvidia's CUDA, ATI's Stream, and Apple's OpenCL frameworks. There aren't many apps available yet that take advantage of these relatively new technologies, but the ranks are slowly growing. The latest GPU-assisted app to come available is one designed for IT managers to make sure their wireless networks are secure--and inevitably for hackers to try to break into wireless networks.
Russian-based ElcomSoft has just released ElcomSoft Wireless Security Auditor 1.0, which can take advantage of both Nvidia and ATI GPUs. ElcomSoft claims that the software uses a "proprietary GPU acceleration technology," which implies that neither CUDA, Stream, nor OpenCL are being utilized in this instance. At its heart, what ElcomSoft Wireless Security Auditor does is perform brute-force dictionary attacks of WPA and WPA2 passwords. If an access point is set up using a fairly insecure password that is based on dictionary words, there is a higher likelihood that a password can be guessed. Brute force attacks that send random dictionary words to an access point can eventually successfully guess the password, if given enough time--the more computational power behind it, the faster the software can send passwords attempts and possibly guess the password.
http://hothardware.com/News/GPUs-Use...iFi-Passwords/
GPUs Used To Crack WiFi Passwords Faster
GPUs Used To Crack WiFi Passwords Faster 
