Re: John Gilmore and the Great Internet Snake Drive

[John Gilmore <gnu@om.toad.com>]

> One lesson I plan to observe - don't encrypt known plaintext unless you
> have to !

The EFF DES Cracker cracks more than just known plaintext (though it's
the easy case).  It also cracks plaintexts whose likely byte values
are known (e.g. all alphanumeric), winnowing the keyspace down to a
size that software or humans can search.  Such a search runs in very
close to the time required for an ordinary known-plaintext search.
See the book for details (www.oreilly.com).

We successfully cracked a DES-encrypted Eudora saved-mail file
provided by Bruce Schneier during our debugging period.  He gave us
the top byte of the key so we could focus on debugging rather than on
waiting to get to the right block of keyspace.  The machine located
the key within that 49-bit keyspace after we fixed a few software
bugs.

	John