"Code crackers break 923-bit encryption record"

[Mem5]

"Code crackers break 923-bit encryption record" http://news.cnet.com/8301-1009_3-5745747...on-record/

They use 21 computers for 252 cores in total.
Do you know why did they use CPUs to bruteforce the key ?! GPUs seem to be a better choice here.
How many weeks/months do you think it would take with a HD 6990 for example ?

[Bitweasil]

Does anyone know what algorithm they broke the keys for? I don't see it mentioned anywhere.

And Mem5 - some algorithms simply don't scale well to GPUs. If the analysis is heavily branchy, or has large memory requirements (100s of MB per thread), GPUs just don't work for it.

[NeonFlash]

That's true. Would be interesting to know the details of the key generation algorithm which was cracked by them.

As stated already, some algorithms like bcrypt cannot be accelerated on GPU platform. They have high memory requirements, as in, they make multiple accesses to a 4 KB array of S-boxes.