Reuters: Woman Enigma Cracker Ignored

[Q G Campbell]

Owen

The story about the importance of the keyboard to entry ring mapping is
more interesting and important than your excert suggests. That "one of
Mrs BB's senior colleagues discounted her theory...because he could not
believe that the Germans had been so stupid" suggests that she worked in
Dillwyn Knox's section of GC&CS.

Knox headed the early work in GC&CS on the unsteckered commercial Enigma
that was used by the Italians and by the Fascist forces in the Spanish
Civil war. He was able to break messages enciphered with this machine
using his "petits batons" method.=20

Knox exploited one of the flaws in the Enigma which was the positioning
of the "fast" rotor in the rightmost position. Input from the keyboard
fed into this rotor. Knox used the term "QWERTZU" for the mapping of the
keys to the entry ring of the fast rotor (the Enigma keys on the top row
are QWERTZUIO, unlike on an English typewriter keyboard). On the
commercial Enigma the Q key was wired to the first entry ring contact,
the W key to the second contact and so on.

The steckered German military Enigma had a different mapping from
keyboard to entry ring. Until that could be found then Knox and his team
could not start to determine the internal wiring of the rotors.

Knox was a singular individual with a very particular and elevated sense
of his position in his social and professional world. From what has been
written about him it seems he was perfectly capable of ignoring people
he did not consider his intellectual equal and even then of disregarding
ideas which did not fit his view of how things ought to be ordered.

On July 24 1939 Knox and Denniston flew to Warsaw. This was the second
meeting between the British, the French and the Poles. It was at this
meeting that Knox learnt that the Poles had been reading German military
Enigma traffic since 1933. When the Poles showed the British and French
teams the two Polish copies of the German military Enigma it is said
that Knox's first words were "What is the QWERTZU?"   =20

According to Budiansky [1] "Rejewski's answer infuriated him. The
Germans had wired the keys to the entry ring in alphabetical order. 'A'
was wired to the first contact, 'B' to the second contact [and so on].
It was not so much that Knox was mad at himself for not having figured
it out; it was that he was indignant that a challenging mathematical
puzzle had a trick answer. It was a swindle. It was too simple, and that
was an affront to his sense of the universe."

In fact the Poles had discovered the "QWERTZU" at the end of 1932. They
had obtained from a traitorous German, Hans-Thilo Schmidt, the daily key
settings, including the steckers, for the months of September and
October 1932. The Poles already had quite a substantial amount of
intercepted German military Enigma traffic for that period. =20

Exactly how these stecker settings and intercepted traffic helped
Rejewski finally work out the fast rotor wiring [and then of the other
rotors] is well documented elsewhere. However he needed the entry ring
sequence before he could proceed.

Budianski describes how "Rejewski tried QWERTZU for the entry ring
[mapping] but got nowhere. But, perhaps more imaginative than Knox, or
perhaps better grasping the Germans' lack of imagination, Rejewski
decided to take a wild guess that the order was alphabetical. As if 'by
magic', the solution to the [fast] rotor's wiring began emerging on the
paper before him." The rest is history, as they say.

[1] "Battle of Wits", Stephen Budiansky, Viking 2000, ISBN 0-670-88492-8

Quentin
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> -----Original Message-----
> From: Owen Blacker [mailto:owen.blacker@wheel.co.uk]
> Sent: 16 October 2001 11:06
> To: UK Crypto list
> Subject: Reuters: Woman Enigma Cracker Ignored
>=20
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> =20
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>=20
> http://www.wired.com/news/women/0,1540,47560,00.html
>=20
> | Woman Enigma Cracker Was Disused
> | Reuters
> |=20
> | 6:42 a.m. Oct. 15, 2001 PDT
> |     =20
> | LONDON -- A British woman cracked a key component of Germany's
> | top-secret Enigma encoding machine before World War II=20
> began, but her
> | supervisors dismissed her theory as too simple, according
> to a new book published on
> | Monday.  =20
> |=20
> | British newspapers ran excerpts of the book, Action This Day, which
> | claims that discoveries made by a female codebreaker known only as=20
> | "Mrs BB" could have opened the secrets of the encoding=20
> machine and shortened
> | the war.  =20
> |=20
> | Codebreakers including Alan Turing, the father of the
> modern computer,
> | were trying in the late 1930s to break the Enigma cypher,
> the key to
> | Germany's communication system.
> | =20
> | But they could not figure how the keys of the Enigma
> machine were wired
> | up.  =20
> |=20
> | The book's editors, Michael Smith and Ralph Erskine, said that "Mrs
> | BB" suggested the Germans wired the A key to the A rotor, B=20
> to B and
> | so on through the alphabet -- a theory dismissed as too
> simplistic, but one
> | that proved correct.  =20
> |=20
> | "Surprisingly, one cryptanalyst, a 'Mrs BB,' had seriously
> | contemplated that the wiring was indeed an identity (A to A=20
> etc)," historian Erskine
> | wrote.  =20
> |=20
> | But one of Mrs BB's senior colleagues discounted her theory
> "probably
> | because he could not believe that the Germans had been so
> stupid," he
> | wrote.  =20
> |=20
> | The full Enigma code was finally cracked by a team of
> thousands of men
> | and women, including chess masters, civil servants and mathematics
> | geniuses, laying bare German troop and submarine movements.  =20
> |=20
> | The book also contains chapters written by former codebreakers. Its
> | royalties will be donated to the Bletchley Trust at Bletchley Park,=20
> | the site of a house in north London where codebreakers=20
> laboured before and
> | during the war.  =20
> |=20
> | Copyright (c) 2001 Reuters Limited.
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> - --
> Owen Blacker
> Senior Software Developer / InfoSec Consultant    Wheel: Clerkenwell
> See http://www.owens-place.org.uk/pgp.html -- more about my=20
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