Gordon Welchman was an Englishman who, while working on decoding German messages at Bletchley Park during World War II, invented traffic analysis. His idea was that even if one couldn’t decipher message contents, just tabulating who messaged whom, when, and how frequently, lent knowledge about the enemy.
After the war, he emigrated to America, where he became an American citizen and taught the first computer course at M.I.T. He worked for Remington Rand and eventually for the MITRE Corporation, where he enhanced traffic analysis technology and helped develop C3 (Command, Control, and Communication) systems.
Following the publication of his book The Hut Six Story in 1982, which detailed the work of his Hut Six group at Bletchley Park, his security clearance was revoked. This killed his career in intelligence.
Today we call the information that surrounds a message “metadata”.
(Originally published October, 2014) The new British film The Imitation Game illustrates the remarkable life of mathematician and computer science pioneer Alan Turing. It will open in theaters on November 21.
This 30-minute video interview with the film’s director Morten Tyldum, actors Benedict Cumberbatch and Keira Knightley, and screenwriter Graham Moore, is worth watching. I can’t wait to see the movie. I’m happy that the screenplay is based on Andrew Hodges’ definitive biography Alan Turing: The Enigma. (Hodges is a mathematician, so if you’d like, he can walk you through Turing’s reasoning based on number theory that led to the routine decryption of messages that were encrypted by the German Navy’s Enigma machines.) Hodges’ biography is a wonderful book that I use as a reference.
Screenwriter Moore describes Mr. Turing as “the outsider’s outsider”. Director Tyldum calls The Imitation Game “a story about outsiders, those who are different.” “The mission of the movie is to celebrate uniqueness — individuality.”
Update, 28 Dec 2014 Mathematician Simon Singh saw the movie and quipped in a Science Friday interview that it’s “filled with factual errors, full of flaws, and in that respect it’s a terrible, terrible film” but in other ways it’s a “brilliant, great film”. According to Singh, the movie errs in dozens of details. Notable errors:
At Bletchley Park during WW2, Turing is shown building a general purpose computer dubbed “Christopher”, which supposedly was used to decipher scrambled German messages that had been encrypted with the Enigma machine. This is wrong. Turing did create the algorithms for, design, and participate in the construction of multiple dedicated electromechanical single-purpose calculators that were used to decipher Enigma-encrypted messages. These machines were called bombes.
In 1952, through detective work, the Manchester police discovered that Turing was a homosexual. In fact, Alan’s flat was burgled by, he suspected, a homosexual paramour. Outraged, he reported it to police, and mentioned that, yes, he had had a few trysts with the suspect. The police charged him with “lewd and indecent acts” (the same crime that had put Oscar Wilde behind bars a few decades earlier).
I view these errors as serious flaws, but I suppose that Hollywood feels a need to juice up the facts.
November 2015: I’m not going to watch this movie. Reviews by knowledgeable people who’ve seen it decry its many inaccuracies. Just one of many negative reviews on IMDB:
Another Weinstein production that is obvious and sad. Pushing the main Hollywood agenda of homosexuality. Sad and practically comical A very demeaning exploitation of the real heroes and suffering in WWII and woe is the lone gay guy losing the battle to the evil empire of the moral world. Save your money. The acting was made trite by the twisted story and the depth was a deep as a sippy cup. Really disappointing but of course will get tons of attention due to the publicity budget from this group. This once again confirms that you can no longer see a big name production without expecting the story to be trivialized and contain the jaded view of the liberal left who is in a ship going down.
If necessity is the mother of invention, war is its father. Both automated encryption/decryption and radar technologies blossomed during World War Two. An excellent documentary on YouTube tells the see-saw story of Germany’s WW2 U-boats. The keys to neutralizing them were code breaking and airborne microwave radar.
This 2-hour 34-minute video shows that the German submariners’ fates swung from invincibility to doom, as the Allies deployed various defense technologies.
I was surprised to learn how ineffective the U.S. Navy was, early in the war, at defending our own shores. The U-boats sank 400 merchant ships near our coastline! Apparently we have Admiral King to blame for these staggering losses. He was at the time in charge of defending our eastern shore. Always an Anglophobe, he distrusted the decrypted German Naval messages that were provided to him by the English codebreakers.
If, like me, you’re fascinated by the relationship between war and technology, watch this video.
English mathematician Alan Turing, who in 1952 was convicted of “gross indecency” (read: homosexuality), today received a pardon from Queen Elizabeth. His death in 1954 was ruled a suicide. His work at Bletchley Park had led to the breaking of the German naval Enigma code during WW2. BBC story: http://www.bbc.co.uk/news/technology-25495315
I’ve written a bit about Alan Turing and Bletchley Park’s successful effort to decrypt WW2 German Navy messages that were encrypted by the Germans’ Enigma machine. This amazing feat at Bletchley Park allowed supply ships to escape the U-boats so England could survive the early years of WW2.
In 1942, the Germans introduced their Lorenz encrypting teleprinter machine which the Brits dubbed Tunny. Enigmas contained 3 to 5 encrypting wheels; Lorenz contained 11 wheels. All German high command messages were encrypted by the Lorenz machine.
The BBC recently produced an excellent video documentary about the cracking of the Lorenz code at Bletchley Park. Bill Tutte did the math and Tommy Flowers designed and built the Tunny decryption machine. They named their decryption machine Colossus, for a reason: it was big.
Bletchley Park used electromechanical “Bombes” to decrypt Enigma messages. Tommy Flowers’ Colossus was truly electronic: it contained 2500 vacuum tubes (“valves” in Britspeak) as well as telephone-type relays. It’s sometimes called the first electronic computer. It reduced message decryption time from 6 weeks to 6 hours. Excellent IEEE video with close-ups of Colossus.
I was vaguely aware that Alan Turing laid the mathematical foundations for computing and was a leader in the wartime breaking of the German Enigma code by the English. Then in the 1980s I read Andrew Hodges’ biography of Turing, titled The Enigma, which helped sharpen my image of Alan Turing. Born in 1912, he thought of numbers as mere symbols, which led to his becoming a powerhouse in number theory. Before World War 2, number theory was a quiet corner of mathematics of seemingly no practical use. Before the war, Alan studied at Cambridge and Princeton, and in a famous paper, proposed a “universal machine”, which he proved mathematically could perform the functions of any other machine. Then Germany attacked England and used Enigma machines to encrypt its military messages . . .
The stack of rotors inside an Enigma machine, consisting of three rotors and Umkehrwalze-B (the reflector).
The story of the decoding of German encrypted messages deserves at least several books. The Wikipedia article entitled Cryptanalysis of the Enigma is excellent. There were multiple generations of Enigma machines, whose encrypted messages became increasingly difficult to crack. Each German service employed different Enigma operating protocols, from weak to robust. Turing’s number theory work led to the development of the bombe, a machine that was used to decode Enigma encrypted messages. From June 1941, the Brits routinely decoded German U-boat messages, which brought the sinking of supply ships to a halt. England would not be starved to death.
The Germans subsequently deployed the Lorenz teleprinter machine, whose encrypted messages were eventually decrypted by a massive electromechanical machine with vacuum tube “valves” the Brits called Colossus.
After the war, Turing worked on the design and development of digital milestones, including the ACE and Manchester Mark 1 computers. He pioneered Artificial Intelligence and used mathematics to model and predict biological behavior. He died in 1954 at age 42. He’s believed to have poisoned himself with cyanide, but there’s evidence that his death may have been accidental.
The biography The Enigma is complete — maybe too complete, but the central character remains fascinating. From a book review on Amazon by Thomas D. Jennings:
“. . . Turing was a difficult person: an unapologetic homosexual in post-Victorian England; ground-breaking mathematician; utterly indifferent to social conventions; arrogantly original (working from first principles, ignoring precedents); with no respect for professional boundaries (a ‘pure’ mathematician who taught himself engineering and electronics).”
Galileo, Newton, Maxwell, Tesla, Einstein, Armstrong, Shannon, Turing . . . the list of Promethean giants is long. What do they have in common? I think that the review by Tom Jennings got it right: they were “utterly indifferent to social conventions; arrogantly original (working from first principles, ignoring precedents)”.