From: stewarts@ix.netcom.com
Date: Sun, 24 Nov 1996 18:11:42 -0800 (PST)
To: cypherpunks@toad.com
Subject: The American Black Chamber - Yardley - Re: 1996 Codebreakers
Message-ID: <1.5.4.32.19961125021110.003ad168@popd.ix.netcom.com>
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Adam Shostack <adam@homeport.org> wrote:
>	I just got a review copy of the new (1996) ed. of Kahn's The
>Codebreakers from my local used bookstore.  Its a little disapointing,
>about 20 new pages of material.  Kahn states in the forward that all
>the new material is in a chapter at the end.
.......
>	Anyway, copies should be in bookstores soon.  If you don't
>have a copy already, Kahn is the definitive history book, and is well
>worth having.

I just got a copy* of the 1981 "The American Black Chamber", by
Herbert O. Yardley, with a new (1981) intro by Kahn. ISBN 0-345-29867-5.
The original had been published in 1931, went through a couple printings,
and sold twice as many copies in Japan as the US.  In 1933 the US passed a 
law banning the publishing of any material that had been published in
diplomatic codes, and of course they withheld permission for future printings.  

Lots of good material on the state of crypto from WWI through the 1920s.
Crypto wasn't yet on a mathematical basis, though it was starting to
emerge in cryptanalysis.  After the World War ended, most of the traffic was
cracking diplomatic correspondence, especially for disarmament negotiations.
Getting users to take crypto seriously was a problem - most of the US
communications during the Spanish-American war used a sort of "rot-1898",
and even during the World War, military plans were often broadcast on
radio using wimpy codes, causing much damage to both sides.  
Codes were generally designed by people who didn't have extensive cracking 
experience, and therefore most new codes were easily cracked as well.
  
Yardley's organization diverted some of its expertise to cracking secret
inks, which were extensively used by German spies.  Language and cultural
differences caused surprising difficulties - there was one person they could
find who knew German shorthand systems, and finding Japanese language
experience after the war was difficult, since they didn't want to use
Japanes immigrants for security reasons and most missionaries wouldn't do
military work (both for ethical reasons and because it would lead the
Japanese government to crack down on missions to Japan, Korea, and China.)

Kahn speculates that the ability to crack Japanese naval codes in WWII was
probably enhanced by Yardley's people's work - PURPLE was much stronger
than the earlier Japanese diplomatic codes, but the Japanese Navy believed
that "This time, it's all right" (cable chief, to foreign minister :-),
when it wasn't.

Yardley reports at the end of the book that he believed the science of
cryptography would die out - AT&T had invented a cypher machine during
the war, and had invented one-time pads, and the combination would make
code clerks obsolete and codes unbreakable......

Shortly after that, in 1929, the new Secretary of State was shocked to 
discover that his department was funding eavesdropping. 
        "Gentlemen don't read each others' mail."

#			Thanks;  Bill
# Bill Stewart, +1-415-442-2215 stewarts@ix.netcom.com
# You can get PGP outside the US at ftp.ox.ac.uk
#     (If this is posted to cypherpunks, I'm currently lurking from fcpunx,
#     so please Cc: me on replies.  Thanks.)