[RC5] RSA Secret-Key Challenge Termination

Jim C. Nasby decibel at distributed.net
Mon May 21 11:13:14 EDT 2007

On Mon, May 21, 2007 at 08:53:35AM -0400, Greg Lobring wrote:
> Personally I don't foresee myself continuing to crunch RC5-72 keys with the
> discontinuation of the challenge by RSA. In fact, I've already disabled the
> RC5-72 project on all my clients, they are doing only OGR work now. As it
> stands with yesterday's stats, it could be well over 1,000 years before
> RC5-72 is done. Even with progressing technology, I don't see that
> diminishing too much in my lifetime. I've put over 1,630 days (over 4 years)
> into the project, and seeing it at only 0.415% complete is a little
> depressing!

Something worth mentioning... we have been working on cores for both PS3
and Nvidia (yes, as in video cards) that obtain keyrates pushing
200Mkeys/sec. To put that in perspective, 200Mk/s would put you at the
#66 spot in yesterdays stats. It would take less than 700 of these
clients to *double* what the rest of the entire network did yesterday.

To answer the next logical question... no, we don't have optimized OGR
cores for those devices yet, and it's not clear (to me at least) what it
would take to make that happen. An advantage to RC5 is that it's fairly
easy to translate into assembly or similar low-level languages to gain
huge performance benefits. OGR is substantially more complex which makes
this much harder to do.

Personally, I think it would be a shame to officially close RC5-72
without at least taking these new cores for a spin.
Jim C. Nasby, Database Architect            decibel at distributed.net
Give your computer some brain candy! www.distributed.net Team #1828

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