[wordup] Key to breaking Enigma was in the patent?

[Adam Shand]

from the "why you don't register detailed schematics of your encryption
device with the enemies patent office" department.  heh.

From: The Eristocracy <Eristocracy at merrymeet.com>
URL:  http://www.telegraph.co.uk/et?ac=004782403739693&pg=/et/01/4/20/ncyph20.html

By Michael Smith
Friday 20 April 2001

BRITAIN'S wartime codebreakers could have cracked the German Enigma cipher
machine much earlier if they had followed a diagram for the commercial
version lodged with the British Patent Office in the mid-1920s, documents
released to the Public Record Office show.

But the codebreakers did not believe that the German army would have been
so stupid as to use the same simple wiring system as the widely available
commercial machine for their military equivalents. The Code and Cypher
School, commonly known by its wartime home at Bletchley Park, was fully
aware of how the commercial machine worked in the mid-1920s.

Chiffriermaschinen Aktiengesellschaft, the German company that
manufactured it, had offered the British Government commercial Enigma
machines at a price of $190 each in June 1924. Britain declined to take up
the offer, waiting for the Germans to register it with the British Patent
Office.

Then they obtained the description of how it worked from the patent
officials, including detailed plans of the make-up of the commercial
machine.The files show that, contrary to what had previously been thought,
British codebreakers were working on the Enigma machine during the 1920s
and 1930s.

But they did not manage to break the military variant until early 1940
after gaining vital help from the Poles. The Enigma machine looked like a
typewriter. Pressing the keys sent an electrical impulse through a series
of circuits wired through rotors that moved with each tap of the key,
constantly varying the cipher.

British codebreakers had made a good deal of progress in breaking the
military version but were held up because they could not work out the
order in which the typewriter keys were wired into the internal circuits.
"The Germans weren't idiots," said Peter Twinn, one of those who broke
Enigma. "When they had a perfect opportunity to introduce a safeguard to
their machine by jumbling it up, that would be a sensible thing to do."

It was not until July 1939, when they met their Polish equivalents who had
broken early versions of the machine, that they found out that it was
wired alphabetically, A to the first contact, B to the second contact and
so on. This was the same as in the diagram attached to the patent
application but was so obvious that the codebreakers never even considered
it as a possibility.

Six months later, codebreakers made their first break into Enigma,
something they could have done far earlier if they had only tried the
alphabetical system in the patent application."It was such an obvious
thing to do, really a silly thing to do, that nobody ever thought it
worthwhile trying it," said Mr Twinn.