This might be dangerous...

[NeoGen]

There's a new hacker's project out there...
http://reflextor.com/trac/a51


Creating A5/1 Rainbow Tables (http://reflextor.com/trac/a51) is decrypting the A5/1 algorithm used in GSM (Global System for Mobile communications) to demonstrate the insecurity of the algorithm. Over 80% of the world's mobile phone market, used by 3 billion people in 200 countries, uses this encryption algorithm. If the project is successful, its results "will allow anyone with some RF equipment, patience, and a $500 laptop, the ability to decode GSM-based conversations and data transmissions."
(from distributedcomputing.info)

And best of all, this project seems to be using CUDA already. And from their FAQ's they're planning to have a boinc infrastructure in place soon too...

[txt.file]

The best thing is that this project uses CUDA under Linux. And the topic is also very good so I will support them with my GeForce 8600GS as soon as I have enough free time.

[Nflight]

I agree this could be a dangerous situation. I will not be participating this project.

[Brucifer]

In reading the "quote" in Neo's initial post in this thread, I don't see where this project is good. It will allow little Johnny to decrypt phone conversations..... Uncle Sugar has to go to court to do this, called tapping peoples phone lines..... accomplishing the same thing, one is wired land lines, the other wireless, and just adds more problems for many people in the world. Invasion of privacy. This is not a government sponsored challenge to crack a key like the RC5 series with the end result being to help the govt increase security. This reads like an outright effort to crack peoples phone conversations, and if that is the case, then it is wrong and should not be supported.

[plonk420]

i think this gets into white hat/black hat stuff i'm not very familiar with... if a group of hobbyists can do it, what's to say a mafia-like group like these guys (http://en.wikipedia.org/wiki/Russian_Business_Network), or unsavory goverment hasn't done it? if it's broken, there's a pretty big obligation to fix it.

on another subject, i know little about encryption, but i hope that/wonder if GSM has ideas similar to AACS for blu-ray... (not that blu-ray has dodged being cracked... only keys from leaky players, AFAIK. the AES behind it definitely hasn't) http://forum.doom9.org/showthread.php?t=122363