From: The Deviant <deviant@pooh-corner.com>
Date: Sun, 24 Nov 1996 20:40:53 -0800 (PST)
To: Bill Frantz <frantz@netcom.com>
Subject: Re: IPG Algorith Broken!
In-Reply-To: <199611242349.PAA02899@netcom6.netcom.com>
Message-ID: <Pine.LNX.3.94.961125043454.344A-100000@random.sp.org>
MIME-Version: 1.0
Content-Type: text/plain


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On Sun, 24 Nov 1996, Bill Frantz wrote:

> At  2:16 PM 11/24/96 +0000, The Deviant wrote:
> >On Sat, 23 Nov 1996, Bill Frantz wrote:
> >> I thought Shannon proved one-time-pads to be unbreakable using information
> >> theory.
> >
> >Different ball game.  OTP isn't "unbreakable" .  OTPs are secure because
> >no matter what key you use, it _will_ decrypt, so your plaintext is still
> >hidden simply because it could decrypt to whatever the person trying to
> >decrypt it wants it to.  Its not that its unbreakable, its that its
> >breakable in _so many ways_.  
> 
> I think we differ on the definition of "unbreakable".  A quick stab at my
> (admittedly very vague) definition includes the inability of the analyst to
> determine (by the structure of the plaintext) that he has a correct
> decryption.

Well, I was speaking mathematicly (sortof).  When I say "unbreakable", I
mean that you can't figure out the plaintext given only the cyphertext.
In this sence, you can't prove an algorithm "unbreakable", for the reasons
stated *so many times* on this list, and OTP is very very breakable, but
the information you get after breaking it isn't usefull to you.

 --Deviant
   PGP KeyID = E820F015 Fingerprint = 3D6AAB628E3DFAA9 F7D35736ABC56D39

"It's kind of fun to do the impossible."
                -- Walt Disney


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