Re: Other Efforts

Greg Trotter (greg@ou.edu)
Wed, 11 Jun 1997 16:56:07 -0500


At 2:42 PM -0500 6/11/97, Ryan D Pierce wrote:
>Of course sequential searches in a competitive environment can be bad;
>they give the opponent info about exactly what keyspace you've already
>searched and what keyspace you will search next. If we have 100 keys, I
>have equal processing power as deschall, and I check out a deschall key and
>get 12, I then can start cracking at, say, 15 while the next key deschall
>searches is 13. I can then cover 15-100 sequentially before deschall does,
>and if the key lies there, I am guaranteed to find it before deschall.

Or, again assuming two competitors with the same keysearch rate, and
assuming a keysearch of 100 keys... if you know the competition goes
sequentially starting at 1, then you just have to start at 2. That gives
you a 99% chance of finding the key before the competition. Pretty much the
same concept.

Either way is a strong argument against a sequential search. Sequential
searches are sufficient for finding random keys in a non-competitive
environment -- which is not what we are in now.

- greg

--
Greg Trotter
Production Manager, Student Publications
The University of Oklahoma
greg@ou.edu