First released at Shmoocon 2005, the WPA lookup tables were a project of the Church of Wifi to apply the time/memory tradeoff to WPA-PSK and WPA2-PSK password cracking.
It's been known for a while that WPA-PSK was vulnerable to brute force attack. Tools like Aircrack and coWPAtty took advantage of this weakness and provided a way to test keys against dictionaries.
Problem is, it's a very slow process. Each passphrase is hashed 4096 times with SHA-1 and 256 bits of the output is the resulting hash. This is then compared to the hash generated in the initial key exchange. A lot of computing power is required for this.
To complicate matters, the key hash can be different depending on the network it's implemented on. The SSID and the SSID length is seeded into the passphrase hash. This means that the passphrase of 'password' will be hashed differently on a network with the SSID of 'linksys' than it will on a network with the SSID of 'default'.
For the Defcon 13 Wardriving contest there was one contest that was particularly infuriating. "The Last Crusade" had contestants attacking a series of access points to connect to a server behind it, each one's security was stronger than the previous. The last AP was WPA-PSK. 3 hours was slated for the contest, 1 hour was spend on the 4 previous APs'. We spent the last 2 hours running coWPAtty on 2 laptops and ended up failing to get the key. The last 2 hours were very boring.
After the contest I began thinking that there had to be a better way. Eventually the planets aligned and I figured out a way. Problem was, how to get it accomplished.
Before I get too far, This project was initiated by RenderMan but with a huge amount of help and support from many others. It's their work that should be applauded. Ideas are cheap, work is not.
RenderMan: Initiator, argent provocateur
Joshua Wright: Original author of coWPAtty, added code to make this project a success.
Thorn: Moral support, sounding board, critic
Dragorn: Ass saving CPU wrangler and cool guy
H1kari: FPGA god who gave us access to dedicated hardware for generating these tables
Twitchy: CPU Wrangler and all around great guy
Other peoples' work contributed indirectly to this, but they deserve mention:
Beetle: CPU wrangler for the Shmoo groups rainbow tables
Dan Moniz and Patrick Stach: Fellow Shmoo rainbow table conspirators
Philippe Oechslin: For a kick ass paper on the Time-Memory Trade-Off