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. *
"Advanced dictionary attacks with deep mutations attempt multiple variants and combinations of each dictionary word. The mutations can be fine-tuned to employ all or some of the settings such as different letter cases, number substitutions, changing the order of characters, using abbreviations and vowel mutations; 12 configurable mutation settings altogether."
ElcomSoft positions the software as a way to "audit" wireless network security. However, we're fairly certain that at least some users will use the software for more nefarious means, such as trying to break into someone else's wireless network. If you manage a wireless network, you should use passwords that use a combination of upper and lower-case letters, numbers, and symbols (if it supported), use relatively long passwords, and avoid dictionary words--in fact, this is good advice for nearly any type of password--not just for wiresless access points. ElcomSoft Wireless Security Auditor runs on Windows NT SP4, Windows 2000, Windows XP, Windows Vista, Windows Server 2003, and Windows Server 2008. The software ordinarily sells for $1,199, but is currently selling at half price ($599.5) until March 1, 2009.
* UPDATE: ElcomSoft Wireless Security Auditor does not actually send continuous random passwords to a router in a traditional brute-force attack: "Elcomsoft Wireless Security Auditor works completely in off-line, undetectable by the Wi-Fi network being probed, by analyzing a dump of network communications in order to attempt to retrieve the original WPA/WPA2-PSK passwords in plain text." "Elcomsoft Wireless Security Auditor requires a valid log of wireless communications in standard tcpdumptcpdump. The tcpdumptcpdump format is supported by all commercial Wi-Fi sniffers. In order to audit your wireless network, at least one handshake packet must be present in the tcpdump file."