From: John.Nieder@f33.n125.z1.FIDONET.ORG (John Nieder)
Date: Sat, 27 Feb 93 07:19:45 PST
To: cypherpunks@toad.com
Subject: Re: DES
Message-ID: <5085.2B8EFE60@fidogate.FIDONET.ORG>
MIME-Version: 1.0
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 * Reply to msg originally in Cypherpunks         <INET>

 phiber@eff.org (Phiber Optik) writes:

 BK> Slow down.  Firstly, DES encrypts a 64-bit block with a 56-bit key.
 BK> Are you talking about key lengths?

Yes.

 BK> It was originally proposed to use a
 BK> 128-bit key space, alla IBM's LUCIFER.  But they opted on the smaller
 BK> key, which fuels this NSA conspiracy theory.

As was their reaction to Hellman's proposal for a 64-bit key and any
other proposed out-of-house improvement at that time.

 BK> Saying that Hellman "broke" anything is a bit
 BK> strong.  I remember reading a published paper, I believe by Hellman and
 BK> one other, describing that they were able to WEAKEN DES (with a smaller
 BK> key space for their experiment), using a statistical approach, and that
 BK> this could possibly be applied to the DES standard.

I refer you to Warren on this.  It was my understanding of the article
that Hellman had actually decrypted DES cyphertext prepared with the
then-proposed 54-bit key standard.
 
 BK> If you're not just some NSA-paranoid wacko,
 BK> reference some papers to back up your claims.  Otherwise, you're just
 BK> another NSA-conspiracy theorist, and part of the noise.

Please, there's no need for abuse here.  I was referring to a published
column by Jim Warren of the Electronic Frontiers Foundation in
_MicroTimes_, a Bay Area computer paper.  I do not know if you consider
Warren or the EFF to be reputable.  I assumed Warren's statements were
factual.  The assertion that Israeli intelligence made short work of DES
was presented as I got it - an interesting rumor from someone who has
been a fairly-reliable source of information in the past.

 BK> We're all
 BK> capable of suspecting underhandedness on the part of the NSA, but when
 BK> you start misrepresenting your opinions as fact, you're being
 BK> nonconstructive.

I was merely relating published assertions by the EFF.  If you believe
these to be incorrect, then I'd advise you to take the issue up with
Warren.  I have no "opinion" in the matter, only suspicions.  A great
many people with academic background superior to mine also share these.
My own background is in applied rather than theoretical security.  I
defer to academics in academic matters, but know that in matters of top
security it is difficult to invest confidence in any mechanism as mired
in continuing controversy as DES.  That's all.

        JN
        

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