From: Bill Stewart <stewarts@ix.netcom.com>
Date: Sat, 24 Feb 1996 16:54:22 +0800
To: cypherpunks@toad.com
Subject: Re: Internet Privacy Guaranteed ad (POTP Jr.)
Message-ID: <199602240738.XAA15114@ix3.ix.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


At 11:08 AM 2/22/96 -0500, SINCLAIR  DOUGLAS N <sinclai@ecf.toronto.edu> wrote:
>What they have gained is the knowledge that their random number source
>isn't broken.  If your RNG started spewing 0 bits by the thousand would
>you say "This stream is just as likely as any other stream that I can
>imagine so there is no problem", or "My RNG is broken".  Of course,
>in nice mathematical abstractions your RNG never breaks, but we live in
>a nasty world of thermal failiures and cold solder joints.

They _haven't_ gained that knowledge, only the knowledge that it isn't
_totally_ broken and spewing zeros.  For example, the output of
       while(1) printf("%8c", des(i++, key));  // Pretend syntax is correct
would probably pass the randomness tests just fine, in spite of being entirely
predictable and having only 56 bits of key plus log(i) bits of state, 
and is  vulnerable to most cryptanalysis attacks on DES systems as well.
But it's not a One Time Pad, it's just counter-mode DES.

#--
#				Thanks;  Bill
# Bill Stewart, stewarts@ix.netcom.com / billstewart@attmail.com +1-415-442-2215
# http://www.idiom.com/~wcs     Pager +1-408-787-1281