Enigma vs Tractatus (was Re:Left wing blogs

[Justin Schwartz]

>Was Enigma a complex polyalphabetic cipher or a scrambler? I remember
>working during training with a u.s. army machine which was
>polyalphabetic. It could be read fairly easily if one were sitting at a
>desk with leisure to spend but probably would have been pretty difficult
>to read if shells were bursting around, no desk at which to copy the
>cipher text neatly on large sheets of graph paper -- and to be useful a
>decipherment was needed in an hour or two.
>

It was a scrambler. The machine had 4 (later 5) wheels with the German 
alphabet that worked on an electric circuit. Given an initial setting, if 
you typed in, say "s", it would output "q" (or whatever). The number of 
combinations was basically insoluable by then contemporary computing 
technology. The code was cracked (or a time) because we got the weather book 
with some initial settings from a disbled U-boat. Later the foalks at 
Bletchtly Park were able to figure out that they clear cast the weather 
settings, so they were able to work backwards given the handful of letter 
groups they got. An mazing piece of technology. We have a couple in Chicago; 
there's one in the Smithsonian. Looks like typewriter, basically.

You can read about how they did it in Geoff Hidgson's Alan Turing, The 
Enigma, a wonderful acount of a great and rather bent sort of mind. T was 
gay, depressive, and unimaginably brilliant, a part of the efferversence of 
interwar Cambridge that included Wittgenstein, Keynes, Piero Sraffa, and 
Frank Ramsey (possibly the smartest person of the 20th century, died 
tragically young). There's a popular but basically accurate account of how 
it was done (leaving out the fictional caharcters) in Robert Harris' popular 
mystery Enigma.

jks

jks

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