[rc5] RC64 keyspace

Joseph Fisk joe at rm405n-a.roberts.fit.edu
Mon Oct 27 22:07:52 EST 1997


On Mon, 27 Oct 1997, Ryan Krueger wrote:

> >So the best way we have to break the encryption is to use brute-force.
> >Unless you know something we all don't.  ;-)
> 
> This is not true.  All encryption techniques have flaws.  There are 
> mathematical ways to elimate portions of the keyspace.  This depends on 
> the encryption method and your knowledge of the problem:  known 
> plaintext, unknown plaintext, etc.  Now, we have an easier one:  known 
> plaintext--we know a portion of the plaintext!

The point, however, is that with OTP encryption, there IS no keyspace.

> Of course, the point of Bovine (and the rest) is to prove that low bit 
> encryption is susceptible to brute force.

And it's not even that susceptible.  It took 250 days for 25,000 machines
to find the key to a single message.  Sure, if the government really
wanted to know the contents of a single message encrypted with rc5/56,
they could do so eventually (remember, they have no plaintext to compare
to either).

Joseph

**************************************************************************
** C. Joseph Fisk (mdmbkr)                           mdmbkr at chillin.org **
** Visit http://www.distributed.net - the world's fastest supercomputer **
**************************************************************************


----
To unsubscribe, send email to majordomo at llamas.net with 'unsubscribe rc5' in the body.



More information about the rc5 mailing list