From: frantz@netcom.com (Bill Frantz)
Date: Sat, 16 Mar 1996 22:36:50 +0800
To: cypherpunks@toad.com
Subject: Re: Venona NSA web page
Message-ID: <199603150730.XAA26212@netcom6.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


At 11:42 AM 3/14/96 -0800, Vladimir Z. Nuri wrote:
>------- Forwarded Message
>
>Date:      Wed, 13 Mar 1996 06:59:32 -0500 (EST)
>From: merkaba@styx.ios.com
>Subject:   VENONA PROJECT (fwd)
>
>
>
>
>- - ---------- Forwarded message ----------
>Date: Tue, 12 Mar 1996 22:07:24 -0500
>From: Ronald Pearce <ronald@cybercomm.net>
>To: merkaba@styx.ios.com
>Subject: VENONA PROJECT
>
>http://www.nsa.gov:8080/docs/venona/venona.html
>
>The VENONA Project
>
>In July 1995 the Intelligence Community ended a 50-year silence regarding
>one of cryptology's most splendid successes - the VENONA Project. ...

How they did it (from http://www.nsa.gov:8080/docs/venona/memory.html):

A word about the VENONA cryptosystems---they should have been impossible to
read. They consisted of a code book in which letters, words, and phrases
were equated to numbers. So a code clerk would take a plain text message
and encode the message using numbers from the codebook. This would have
presented a significant challenge itself depending on how long the code
book was used. However, the messages were further modified, in other words
double-encrypted, by use of a one time pad. The use of a one time pad
effectively randomizes the code and renders it unreadable. The key to the
VENONA success was that mistakes were made in the construction and use of
the one time pads---a fact that was discovered only through brute force and
analysis of the message traffic. 

(http://www.nsa.gov:8080/docs/venona/monographs/monograph-2.html):

... One-time pads used properly only once are unbreakable; however, the
KGB's cryptographic material manufacturing center in the Soviet Union
apparently reused some of the pages from one-time pads. This provided
Arlington Hall with an opening. Very few of the 1942 KGB messages were able
to be solved because there was very little duplication of one-time pad
pages in those messages. The situation was more favorable in 1943, even
more so in 1944, and the success rate improved accordingly.

Bill


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