- Haynes, John Earl and Harvey Klehr. Venona: Decoding Soviet Espionage
in America. New Haven, CT: Yale University Press,
1999. ISBN 0-300-08462-5.
- Messages encrypted with a one-time pad are absolutely secure unless the
adversary obtains a copy of the pad or discovers some non-randomness
in the means used to prepare it. Soviet diplomatic and intelligence
traffic used one-time pads extensively, avoiding the vulnerabilities
of machine ciphers which permitted World War II codebreakers to read
German and Japanese traffic. The disadvantage of one-time pads is
key distribution: since every message consumes as many groups
from the one-time pad as its own length and pads are never reused
(hence the name), embassies and agents in the field require a steady
supply of new one-time pads, which can be a logistical nightmare in
wartime and risk to covert operations. The German invasion of the
Soviet Union in 1941 caused Soviet diplomatic and intelligence traffic
to explode in volume, surpassing the ability of Soviet cryptographers
to produce and distribute new one-time pads. Apparently believing
the risk to be minimal, they reacted by re-using one-time pad pages,
shuffling them into a different order and sending them to other
posts around the world. Bad idea! In fact, reusing one-time
pad pages opened up a crack in security sufficiently wide to permit
U.S. cryptanalysts, working from 1943 through 1980, to decode more
than five thousand pages (some only partially) of Soviet cables
from the wartime era. The existence of this effort, later codenamed
Project VENONA, and all the decoded material remained secret until
1995 when it was declassified. The most-requested VENONA decrypts
may be viewed on-line at the NSA Web site. (A few months
ago, there was a great deal of additional historical information
on VENONA at the NSA site, but at this writing the links appear
to be broken.) This book has relatively little to say about the
cryptanalysis of the VENONA traffic. It is essentially a history
of Soviet espionage in the U.S. in the 1930s and 40s as documented
by the VENONA decrypts. Some readers may be surprised at how
little new information is presented here. In essence, VENONA
messages completely confirmed what Whittaker Chambers (Witness, September 2003) and Elizabeth Bentley
testified to in the late 1940s, and FBI counter-intelligence
uncovered. The apparent mystery of why so many who spied for the
Soviets escaped prosecution and/or conviction is now explained
by the unwillingness of the U.S. government to disclose the
existence of VENONA by using material from it in espionage cases.
The decades long controversy over the guilt of the Rosenbergs (The Rosenberg File, August 2002) has been definitively resolved
by disclosure of VENONA—incontrovertible evidence of their guilt
remained secret, out of reach to historians, for fifty years after
their crimes. This is a meticulously-documented work of scholarly
history, not a page-turning espionage thriller; it is probably best
absorbed in small doses rather than one cover to cover gulp.
February 2004 