Re: Plaintext

Stephen Haffly (
Wed, 2 Jul 1997 16:01:27 MST

** Reply to note from "Thompson, Christopher" <> Wed, 2 Jul 1997 14:38:07 -0600
> Something's been bothering me for a few days.
> If we hadn't have known _anything_ about the plain text of the
> DES-encrypted message, we wouldn't have been able to decrypt it,
> even using brute force. Is this correct?
No, it would have made the job more difficult as each attempt would
have had to be checked with something akin to a spelling checker to
see if any legitimate words were there. It probably would have then
needed to be checked all the way through to see if all words were
legitimate just in case one or more words were legitimate, but not
the whole message, as one would expect from a random key attempt. It
would then probably need to be placed in a queue for a final check by
a human to make sure it indeed made sense, as I have yet to see a
grammar checker accurate enough to trust. Then it would have to have
been submitted to verify that the correct key had indeed been
discovered (as was done in reality).

More steps, but the end result would have been the same IMHO.

Stephen Haffly   Homepage:
Team OS/2, Team GEOS
OS/2 and Geoworks Ensemble - What a combo!