DES 2 challenge: Are you going to help?

[Trei Family <trei@relay-1.ziplink.net>]

There's been remarkably little discussion about the DES II contest 
sponsored by RSA labs.

On the 13th, RSA will post another DES challenge, again with a $10,000
prize. There's a new wrinkle: while the prize is still being given to
the first person who reports the key, the size of the prize dwindles as
time goes by. It's $10k for the first 540 hours (about 3 weeks), then drops 
to $5k for the next 540, then $1000, and after 1620 hours drops to 0.

Next June RSA will release another challenge, with the same prize; however
the time limits will ratchet down depending on how fast the key is discovered
this time around. Details are at www.rsa.com

I've heard of only one organized group which plans to attack it; the one
based at www.distributed.net This is the same group which successfully 
brute forced 56 bit RC5 encryption. My educated guess, based on the speed 
with which they are currently searching RC5-64 (about 11 Gkey/sec) and the 
known speed differences between RC5 and DES searching, is that they have 
a good but not certain chance of finding the key within the $10,000 window.
[Interesting factoid - at that speed they could crack 40 bit RC5 keys at
better than one a minute.]

If you have cycles to spare, you might consider joining for the DES attack.
Their clients are quite good, and do not interfere with normal operations.

If you don't want to trust d.n's organizers, consider running Svend
Mikkelsen's
Bryddes for x86 processors. It's quite a bit faster than my DESKR, and full
source
is available.

Peter Trei
trei@ziplink.net