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20 BLETCHLEY PARK AND BEYOND
Habbaniya in Iraq and Sarafand in Palestine. Remarkably, and
despite the growing importance of air power, GC&CS only developed
an RAF section in 1936, under Josh Cooper, a young and
talented code-breaker who had joined the organisation a decade
earlier with a First in Russian from King's College London. 13
Cyphers were important to the Axis military powers. Onetime
pads were slow and cumbersome. Moreover, they were
out of step with the emerging new methods of warfare.
Blitzkrieg, for example, required armoured forces to move
forward at lightning speed, coordinating their activities with
artillery and air support. So the pressure was on to find a way
of making the growing volume of military radio traffic unintelligible
to the enemy. Most developed countries turned to
cypher machines to make their immense volumes of traffic
secure. 14 Complex cypher machines had been pioneered by
banks and businesses - banks had long used fairly simple cyphers
to keep commercial matters secret. In the 1920s, the German
military adapted a Dutch invention to produce the Enigma
cypher machine as an alternative to laborious hand cyphers. In
fact, the first Enigma machines were sold commercially, and
were widely used by banks and businesses. Enigma was what
we now recognise as a 'commercial off-the-shelf solution' to a
difficult military problem.15
The Enigma machine itself looked like an early typewriter in
a square wooden box, but with a keyboard set out in alphabetical
order rather than the traditional 'QWERTY' arrangement.
As each letter key was depressed a set of lights that corresponded
to the alphabet lit up, seemingly at random. The innovation
was the rotors, which looked like fat metal wheels, embedded
in the top of the machine. These rotated and scrambled the
message in a highly unpredictable way. There were initially
three - later four - rotors, with twenty-six positions relating to
the letters of the alphabet. These moved round in a stepping
motion that generated a cypher with an enormous number of
possibilities. Moreover the complex nature of the rotation caused
subtle changes in the stream of material, creating substantial