From: droelke@rdxsunhost.aud.alcatel.com (Daniel R. Oelke)
Date: Sat, 31 Aug 1996 07:11:27 +0800
To: dthorn@gte.net
Subject: Re: Encryption
Message-ID: <9608302028.AA00579@spirit.aud.alcatel.com>
MIME-Version: 1.0
Content-Type: text/plain



I don't have a vested interest other than keeping my data safe.

A *good* cipher will work, even if someone knows the exact 
implementation of it.  Given complete source code to your cipher,
(including the pseudo-random number generator you use) 
and I could easily crack it with about a week's worth of effort.

If you knew anything about cryptography, you'ld know that just
giving someone some cyphertext and challenging them to crack
is not a valid test of the cipher's strength.

Again - go get a copy of Applied Cryptography and don't 
come back until you have read it.

Dan

> 
> Your comments are typical for persons with vested interests.
> Attached is a test file so you can have someone try to crack it.  In the 
> meantime, don't assume because I don't use your favorite methods I don't 
> know what I'm doing.
> 
> Daniel R. Oelke wrote:
> > 
> > Sorry to say this - but your idea stinks.
> > 
> > If you are trying to send something encrypted, your
> > receiving party would need the keys, which are the seed
> > values of the pseudo-random number generators.
> > 
> > Your adversary could keep trying a whole series of
> > different seeds until they found the correct one.
> > With a little more work, they could analyze the
> > pseudo-random number generator that you used, and
> > then work backwards.
> > 
> > Go get a copy of Applied Cryptography Edition II.
> > Don't come back until you have read it.
> > 
> > ------------------------------------------------------------------
[ crap deleted ]

------------------------------------------------------------------
Dan Oelke                                  Alcatel Network Systems
droelke@aud.alcatel.com                             Richardson, TX