Re: [DES-LIST] DESchall

Stephen Langasek (
Tue, 29 Apr 1997 20:52:14 -0500 (CDT)

On Tue, 29 Apr 1997, Nelson Minar wrote:

> Can the person who posted his estimate about the small slowdown if two
> attacks are uncoordinated post that information again, wtih some more
> detail? I remember the conclusion was that it didn't matter if
> deschall and solnet cooperated in divvying up the keyspace or not.
> I'm not sure I believe that.

I'm not the person who posted the original estimate, nor do I have said
estimate on hand, but I will mention that the math holds true if and only
if the number of computers we have to draw on is not a limiting factor. I
don't know that we have any way to tell whether or not it is, not having
polled all the users of the Internet to find out if they would participate
in something of this sort. :) I presume that the actual number of
computers in the world that are networked isn't small enough to be a
limit, however. If we *don't* run out of computers (i.e., the number of
computers continues to grow throughout the entire project), then some
dexterous manipulation of logarithms quickly shows that the time to
completion is only slightly decreased by cooperating. If, however, we
*do* run out of computers (by the time we get near the end, all available
computers are working on the project), then cooperating will result in a
significant time reduction.

Right now, as I said, I don't think there's any way to tell which track
we're on. If we notice, some day down the line, that growth is slowing to
a crawl, we might consider making overtures of cooperation. Until that
day comes, however, I'm all in favor of a bit of competition. Prefer it,
in fact, as we have somewhat of an in-house rivalry at the moment here at
Iowa State, and I would really love to see DESCHALL beat SolNet so I can
rub it in the faces of certain other residents here ;-)

-Stephen Langasek

Help break DES today!