Tuesday, December 30, 2014

A Successful Imitation of Alan Turing

“Sometimes it is the people no one imagines anything of who do the things that no one can imagine.”  The take-away line from The Imitation Game states the theme.  The plot is the quest to build a computer that can decipher enemy communications and win a war.
Even with the Bombe, much work was done manually and brainually.
This grid shown in the movie is not the Banburismus of Turing.
Scholars complain about the historical inaccuracies. It is easy to do.  This is not a documentary. The film is a drama about one man’s achievement of what experts considered impossible.  That much is absolutely true. Commander Alistair Denniston held neither expectation nor hope for success.  The film dramatizes his disdain for the codebreakers. And it is drama, rather than the unemotional grinding out of intellectually difficult, yet ultimately routine, work. 
10,000 people worked there,
80% of them women.
Contrary to the movie, Joan Clarke’s team working on the Naval Enigma had early successes.  In the movie, by mid-1941 Denniston was not the only one enraged by Turing’s lack of progress.  In real life, by then, decipherment of Naval Enigma traffic allowed fleets to be redirected around U-boat packs. Lost tonnage shrank. But it is true that not all intercepts could be acted on. The Ultra Secret by F. W. Winterbotham (Harper & Row, 1974) broke that story long ago. 

Writing in Turing: Pioneer of the Information Age (Oxford, 2012),  B. Jack Copeland acknowledges that Cmdr. Denniston built Bletchley in the early years 1937-1939, though he proved unsuited to the task of managing 10,000 and getting their needs met by arguing for more money and more people. Also, it was late in 1941 when Turing and many others wrote to Prime Minister Winston Churchill, not Turing alone in mid-year. Such quibbles satisfy historians, but do not change the impact of the story.

You can buy a real one.
Some fetch a 6-figure price.
(They also sell replicas - and are not alone in that.)
In real life, although the Turing-Welchman “Bombe” could and did reveal the settings of the Enigma machines, much of its output had to be checked by hand. In fact, Clarke and Turing spent long hours working together in Hut 8. They continued to do so after they broke off their engagement. And they met each other's parents after they announced their engagement. Turing apparently did not meet them before, as in the movie. 

Moreover, different than the portrayal, it was common for all of the cryptanalysts to continue work on the previous day’s cipher traffic until the next round of communiqu├ęs arrived.  They knew of stock phrases - such as ending each message with "Heil Hitler" - because that was long since a basic tool of diplomatic and military cryptanalysis: date at the top; "Your Excellency"; etc.

Turing called his manual labor “Banburismus” after the long sheets of paper made in Banbury.  But Turing called Clarke’s method “Dillyismus” after Dillwin Knox, the World War One cryptologist who revealed the Zimmerman Telegram.

Soon to be an eBook from
Before going to the theater, I intended to watch the film as a story in the abstract, not as a documentary.  That was very hard to do.  I read Andrew Hodges’s booklet biography of Turing when it came out in 1999.  (The film is based on his recent and greatly expanded biography, Turing: The Enigma; Princeton, 2014). Ahead of seeing the film, I researched Joan Clarke and wrote about her for the E-Sylum maillist of the Numismatic Bibilomania Society.  My research into her work continues. Having her numismatic bibliography, from an obituary in the BNJ, I submitted a proposal to the ANA.

From Wired, “How Designers Recreated Alan Turing’s Code-Breaking Computer for Imitation Game,” by Angela Watercutter, November 21, 2014 here
"Turing produced the design for the Bombe, building on the design of the original Polish Bomba which had been produced by Marian Rejewski in 1938. The Bletchley Park Bombe designed by Turing, was refined by another Bletchley Park codebreaker Gordon Welchman and actually built by engineer Harold Keen who was based at the British Tabulating Company, not at Bletchley Park."
A snippet of what displays on
the devices
given to visitors to
perhaps the most computerized park in the UK.

Among those who complain about the film is Dr. Sue Black whose blog is "Cheeky Geek" here.
In a scene stolen from the future,
a tank crushes an (empty) Tommy helmet.
A biography of Joan Clarke's work is this article by Lynsey Ann Lord which is extracted from a University of St Andrews honours project. (Clarke finished all three triposes examinations and qualified for an M. Sc. in addition to her B.A. in mathematics.  She received neither because Cambridge did not grant degrees to women back then.)
Joan Elisabeth Lowther Murray [nee Clarke] (1917—1996) cryptanalyst and numismatist is listed in the Oxford Dictionary of National Biography here

Lord Stewartby (Bernard Harold Ian Halley Stewart), one of her collaborators in the coinage of Scotland, wrote the obituary for the British Numismatic Journal Vol. 67 No. 13, pg 162-167. (Online here.)  In 1986, Joan E. L. Murray was granted a BNS Sanford Saltus Medal for her research. 
He is not really Turing and it is not really his Bombe
but it was still a good movie.

The Secret Lives of Codebreakers: The Men and Women Who Cracked the Enigma Code at Bletchley Park by Sinclair McKay. New York: Plume (Penguin Group), 2012. (Originally published in the UK as The Secret Life of Bletchley Park (Aurum Press).) This retelling of the capture of Enigma wheels from the U-110 has some inaccuracies. The book says very little about Joan Clarke, though quite a bit about Mavis Lever (later Batey), who also worked on the Naval Enigma.

The Ultra Secret: the first account of the most astounding cryptanalysis coup of World War II – how the British broke the German code and read most of the signals between Hitler and his generals throughout the war by F. W. Winterbotham, New York: Harper and Rowe, 1974. This book broke the story. It is not from the viewpoint of Bletchley Park, and has no mention of Turing.

Engima: How the German Machine Cipher was Broken, and How it was Read by the Allies in World War II  by Wladyslaw Kozaczuk, edited and translated by Christopher Kasparek, University Publications of America, 1984 (Warsaw: Ksiazka I Wiedza, 1979).  Polish mathematicians had begun a theoretical analysis as early as 1932. The Turing-Welchman Bombe was an extension of the Polish Bomba; it was not Turing's universal machine


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