The Upcoming DES Challenge

[Lucky Green]

At 06:56 PM 1/6/97 -0800, Mike Duvos wrote:
>Peter Trei (trei at process.com) writes:
>
>Ick.  Why overly complexify things?  A known plaintext attack
>would be far more straightforward.  After all, the goal is to
>recover the key, not the message.  Having to find a key which
>decrypts to something having all high bits clear will discourage
>people who might want to take a crack at this independent of the
>canned program you are going to distribute.

I agree. A real life crack of DES can almost always assume a know plain
text. Why should the demo crack take the 10% hit?

>[snip]
>
> > It will NOT run as a screen saver.
>
>Too bad.  The screensaver paradigm is something the unwashed
>masses can easily understand.

I have been running the distributed prime search software (see my .sig) for
about two months now. [2^1398269-1 is prime!] If you haven't tried this
software, I'd urge you to do so now. Not only because it might make you
famous, but because it will give you some ideas how a distributed DES crack
might work.

I always liked the screen saver idea, but a crack using screen savers only
works while the screen saver is active. The mersenne prime program runs on
the lowest priority thread under Win95/NT/Linux. It works even while you
are working, using all the idle cycles it can find, while at the same time
having no effect at all on any of the work you do. Install it and forget
about it. It's better than a screen saver.



-- Lucky Green <mailto:shamrock at netcom.com> PGP encrypted mail preferred
   Make your mark in the history of mathematics. Use the spare cycles of
   your PC/PPC/UNIX box to help find a new prime.
   http://www.mersenne.org/prime.htm