The Turing Challenge
We have released our most difficult puzzle ever - the Turing Challenge - in honour of Alan Turing becoming the new face of the £50 note, unveiled on the 25th March by the Bank of England.
Head over to the #TuringChallenge homepage to find the puzzles.
Turing is the father of modern computing, a pioneer in artificial intelligence, and instrumental in breaking the German Naval Enigma cipher at Bletchley Park – GCHQ’s wartime home – during the Second World War.
Director GCHQ Jeremy Fleming said
Alan Turing’s appearance on the £50 note is a landmark moment in our history.
Not only is it a celebration of his scientific genius which helped to shorten the war and influence the technology we still use today, it also confirms his status as one of the most iconic LGBT+ figures in the world. Turing was embraced for his brilliance and shunned for being gay. His legacy is a reminder of the value of embracing all aspects of diversity, but also the work we still need to do to become truly inclusive.
Our Turing Challenge, a set of 12 puzzles, has been put together by some of our intelligence staff, where problem solving and a diverse mix of minds are at the heart of our work to help protect the UK from increasingly complex threats.
The puzzles are based on the unique design elements of the new banknote, such as the technical drawings for the British Bombe, the machine designed by Turing to break Enigma-enciphered messages during WWII. GCHQ puzzlers say the full challenge could take an experienced puzzler seven hours to complete.
Colin, a GCHQ analyst and chief puzzler, explains
Alan Turing has inspired many recruits over the years to join GCHQ, eager to use their own problem-solving skills to help to keep the country safe.
So it seemed only fitting to gather a mix of minds from across our missions to devise a seriously tough puzzle to honour his commemoration on the new fifty pound note. It might even have left him scratching his head – although we very much doubt it!
Turing joined the Government Code & Cypher School – GCHQ’s wartime name - in 1938 to help with the code-breaking effort during the Second World War, working alongside Gordon Welchman. Turing was a leading cryptanalyst at Bletchley park, and spearheaded the effort in Hut 8 focusing on the German Naval Enigma. Here he worked closely with Joan Clarke.
In January 1940, Turing met with Polish counterparts in Paris, who gave him the insights he needed to design the Bombe. The Bombe was the first special-purpose British cryptanalytic machine and made a major contribution to the exploitation of Enigma. The combination of the Bombe and the brilliant minds and perseverance of those working at Bletchley Park led to the breaking of Enigma.
In late 1942 Turing went on a liaison trip to the USA where he worked on investigating secure speech systems and helped with the development of what would become the US cipher machine SIGABA. After his return to the UK in 1943 he developed a portable secure voice scrambler (codenamed Delilah) at the secret UK government laboratory at Hanslope Park. His skills at finding and exploiting weaknesses in other people’s systems made him best placed to design new secure systems.
After the War
In 1945, Turing left GCHQ to work at the National Physical Laboratory in London. While there, he worked on the ACE (Automatic Computing Engine) which was the first detailed design of a stored-program computer.
In 1948, Turing joined the Mathematics Department at Manchester University. A year later, he became Deputy Director of the Computing Machine Laboratory. Working with Max Newman, he led a team that produced Britain's first general-purpose stored programme computer (the Manchester Mark 1) and then the first commercial computer (the Ferranti Mark 1). In 1950, Turing turned his attention to artificial intelligence and proposed an experiment attempting to define a standard for a machine to be called “intelligent”, this became known as the Turing Test.
In January 1952, Turing was prosecuted for indecency over his relationship with another man in Manchester. During the trial, Hugh Alexander, the Head of Cryptanalysis at GCHQ, was given official approval to go and speak as a character witness on Turing’s behalf, saying in court that he was a national asset. In March 1952, Turing pleaded guilty to the charges and was given a choice between imprisonment and probation; he chose probation which was conditional upon him undergoing hormonal treatment intended to reduce his libido.
On the 8th June 1954, Alan Turing took his own life.
In a speech for the 100-year anniversary of Alan Turing’s birth in 2012, our then Director Iain Lobban said
We can't rewrite the past. We can't wish mid-twentieth century Britain into a different society with different attitudes. We can be glad that we live in a more tolerant age. And we should remember that the cost of intolerance towards Alan Turing was his loss to the nation.
In a speech at the 2016 Stonewall Workplace Conference then Director Robert Hannigan also paid tribute to Turing as a “a genius, as a problem-solver who was not afraid to think differently and radically”. He also apologised for the historic treatment of the LGBT+ community by the security services, with a security bar to LGBT+ individuals in the intelligence agencies being in place until 1991.
The Notes
The Challenge
Head over to the #TuringChallenge homepage to find the puzzles.
