Ŕ¶Ý®ĘÓƵ professor and WWII codebreaker Dr. William T. Tutte (1917-2002) is one of ten individuals being honored by Great Britain’s Royal Mail in  commemorating the 80th anniversary of Victory in Europe (VE) Day.
Tutte’s stamp, which features his photograph in front of a multi-wheeled code machine, recognizes him for “Codebreaking the Lorenz cipher machine at Bletchley Park.”
The stamp is the British government’s first public recognition of the vital role Tutte played in the fight against Hitler’s Nazi regime.
For half a century, however, his work was top secret.Â
The Puzzle War
Tutte was born in 1917 in the small town of Newmarket, UK, to a working-class family. He excelled in school, winning scholarships first for high school, then to Cambridge University, where he studied chemistry.
From the beginning, he was interested in mathematics and worked recreationally with three friends to solve several famous combinatorics problems. Their theory regarding one of these – dissecting a square into squares of unequal sizes – was published in Duke Mathematical Journal.
A portion of Tutte's notebook examining graph theory from his time at Cambridge University (University of Ŕ¶Ý®ĘÓƵ Archives)
Eventually, this solution would help Tutte earn a reputation as an international leader in combinatorics. First, however, his aptitude for puzzles caught the attention of the British war effort.
Bletchley Park – made famous by Alan Turing and The Imitation Game (2014) – was Great Britain’s top-secret WWII codebreaking research centre. Early in the war, Britain had great success breaking Nazi code encrypted by the Enigma machine, a device that used three movable wheels to create sophisticated ciphers. Soon, however, another mysterious code – nicknamed “Tunny” – emerged. Tunny was being used by Hitler and his generals for vital army communications and was far more complicated than Enigma.
After months of fruitless efforts, the codebreakers got lucky. In August 1941, a German operator in Athens sent a 4,000-character message to Berlin, and – when it didn’t come through properly – he sent the same message again. This time, the operator was lazy: he broke protocol by transmitting twice without changing the encryption settings, and he altered some of his original words and punctuation.
The result was a rich sample of Tunny ready to be broken. A linguist and army officer, Brigadier John Tiltman, manually decrypted the individual message. But, after three months of effort, he and his team were no closer to figuring out how the machine generating Tunny worked.
The Unsung Hero
That’s where Tutte came in. He applied methods he had used in his combinatorics work to look for patterns in the Tunny code, and ultimately was able to determine how the Germans’ Lorenz machine was using twelve wheels to encrypt code. “Thus were the entire workings of the TUNNY machine exposed,” he recalls in a 2000 memoir, “without any actual physical machine or manual thereof coming into our hands.”
Tutte also created a statistical method for strategically attacking encrypted code, allowing Bletchley Park to decrypt intercepted Nazi messages in hours instead of weeks. This intel had a crucial impact on the Russian front, at D-Day and in many other parts of WWII.
 estimate that the information gained by breaking Tunny shortened WWII by two years, saving more than twenty million lives.
“I have met many people in the course of my life who worked at Bletchley and had no idea who Tutte was,” says Dan Younger, professor emeritus of Combinatorics & Optimization and Tutte’s long-time friend. “And they were all working to realize his statistical method for codebreaking! That’s the shame of him not receiving recognition earlier. He was a central figure in the work that was done at Bletchley Park.”
The Codebreaker's Path to Ŕ¶Ý®ĘÓƵ
After the war, Tutte was officially sworn to secrecy regarding his work as a codebreaker. He finished his PhD in mathematics at Cambridge in 1948, and then moved to Canada to work at the University of Toronto. Soon, he became known internationally as a pioneer in graph theory.
In 1962, Dr. Ralph Stanton wooed him to join the brand-new University of Ŕ¶Ý®ĘÓƵ, with promises that he could focus exclusively on his true love of combinatorics. Tutte and his wife Dorothea moved to a quiet home in the country, and for the next two decades he helped create the Combinatorics and Optimization department and cement its reputation as the best in the world.
In 1987, he was made a Fellow of the Royal Society of London for his mathematical accomplishments.
That same year, two years after retirement, Ŕ¶Ý®ĘÓƵ awarded Tutte an honorary doctorate. The citation provided as much information on his war work as was available at the time, noting that he “made the crucial observations that led to the deciphering of one of the German secret codes.”
Secrets Revealed
In the late 1990s, Tutte’s work on Tunny was finally declassified.
In May 1997, shortly before his 80th birthday, an article in New Scientist revealed the mechanics and importance of Tunny, and the role Tutte and other researchers played in cracking it.
In 2001, Governor General Adrienne Clarkson awarded Tutte the Order of Canada, partially in recognition of his wartime achievement.
Tutte died in 2002 at the age of 84. Ten years later, Prime Minister David Cameron wrote a letter to Tutte’s family, recognizing his work’s “enormous value to the war effort” and noting that he “deserves the thanks of the British people.”
“We’re all tremendously happy to see him finally recognized this way,” Younger says of the Royal Mail stamp. “I only wish he had lived to see it.”
°Ő´ÇĚýlearn more, visit the Department of Combinatorics and Optimization’s page about Tutte’s life and research.
