By Tom Morrow
He was a hero of World War II, but no one knew about him until years after the fighting stopped. He was the leading codebreaker at Britain’s highly secret Bletchley Park.
William Gordon Welchman’s cryptic-busting actions during the 1940s cut short the War by at least two years, yet his contributions remained a secret until well into the so-called “Cold War” of the ‘50s through the ‘80s.
Welchman, who was born June 15, 1906, in England, was a mathematician, university professor, and author, but today he is remembered as the key codebreaker at Bletchley Park.
After the war Welchman moved to the U.S., and later took American citizenship. He studied mathematics as a scholar at Trinity College, Cambridge, from 1925 to 1928. In 1929, he became a Research Fellow in Mathematics at Sidney Sussex College, Cambridge, a Fellow in 1932 and later Dean of the College.
Just before the Second World War, Welchman was invited by Commander Alastair Denniston to join the Government Code and Cypher School at Bletchley Park. He was one of four early recruits (the others being Alan Turing, Hugh Alexander and Stuart Milner-Barry), all of whom made significant contributions at Bletchley and who became known as “the wicked uncles.”
They also were the four signatories to an influential letter, delivered to Winston Churchill in October 1941, asking for more resources for the code-breaking work at Bletchley Park. Bletchley’s staff was in desperate need of equipment and supplies. Churchill responded with one of his famed “Action This Day” orders.
As stated in his book, most of Welchman’s work at Bletchley was centered on what was known as “traffic analysis” of encrypted German communications being sent over the infamous “Enigma” machine. He is credited with innovating the approach. This led to data analysis techniques that today we describe as metadata analysis. It’s fair to say that Welchman was the first computer “hacker.”
Welchman devised an enhancement to Alan Turing’s improved code-breaking design for breaking the secret Enigma code used by the Germans. Welchman’s device was called a “Diagonal Board” because such a piece of wire is diagonally across the matrix of connections. The Diagonal Board cut decipher times down from days to mere hours when attacking ciphers generated by the German Enigma machine. The ciphers changed every day, so coming up with a key to read the Nazi transmissions was an almost impossible feat.
Welchman was head of Hut Six, the section at Bletchley Park responsible for breaking German Army and Air Force Enigma ciphers. After the War, Welchman moved to the United States in 1948, where he taught the first computer course at MIT. He then went to work for Remington Rand and Ferranti. Welchman became a U.S. citizen in 1962. In that year, he joined the Mitre Corporation, working on a secure communications systems for the US military. In 1971, he retired, but was retained as a consultant.
In 1982 his book “The Hut Six Story,” was published, which had intelligence agencies in the U.S. and Britain scurrying. While the U.S. National Security Agency disapproved, the book was not banned, but Welchman lost his security clearance (and therefore his MIT consultancy). He was forbidden to discuss either the book or his wartime work. The withdrawal of his security clearance by the NSA after the publishing of his “Hut Six Story” was described as “devastating.”
Welchman died in 1985, but he got the last word in. His final conclusions and corrections to the story of wartime codebreaking were published posthumously in 1986 in his paper “From Polish Bomba to British Bombe: the birth of Ultra.”
Gordon Welchman was the subject of a BBC documentary broadcast on Britain’s BBC in 2015. The program was entitled “Bletchley Park: Code-breaking’s Forgotten Genius,” The program was aired here in the U.S. on the Smithsonian Channel titled: “The Codebreaker Who Hacked Hitler.”
The TV documentary is important because it notes that traffic analysis is now known as “network analysis” and “metadata” analysis and gives as an example the location of Osama bin Laden by the use of network analysis.
In September 2016, a plaque was unveiled by Welchman’s daughter, Susanna Griffiths, at St Mary’s Church, Fishponds, in Bristol. Historians have now acknowledged the harsh treatment of Welchman and have paid tribute to his “immense contribution” as a “giant of his era” and a key figure in defeating the Nazis during World War II.
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