GCHQ releases ‘most difficult puzzle ever’ in honour of gay war hero Alan Turing

Maggie Baska
·3-min read

The Government Communications Headquarters (GCHQ) has released its “most difficult puzzle ever” in honour of mathematician and codebreaker Alan Turing.

The challenge appears on a new £50 note revealed by the Bank of England which features Turing. But the new banknote won’t go into circulation until 23 June – which would have been Turing’s birthday – so the GCHQ has released the puzzle online, too.

The GCHQ said the Turing Challenge requires individuals to solve a string of complex puzzles, which get increasingly difficult, based on the design elements of the new banknote. The puzzle has been put together by some of GCHQ’s intelligence staff, who claim the full challenge could take an “experienced puzzler” seven hours to complete.

Jeremy Fleming, director of the GCHQ, said Alan Turing’s appearance on the £50 note is a “landmark moment in our history”. He explained: “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.”

Turing joined the Government Code and Cypher School – the wartime name for the GCHQ – in 1938 to help with the codebreaking effort during the World War II. He worked with other codebreakers during the war to decode the Enigma code, which was used by Germany and its allies to deliver messages securely.

Turing played a key role in inventing the machine known as the Bombe to help decode this military cypher. And from mid-1940 onwards, German military signals were able to be read by intelligence agents at Bletchley Park, and this information was key in helping the war effort.

The GCHQ said the technical drawings for the Bombe, which is featured on the upcoming £50 note, is one of the puzzles featured in the Turing Challenge.

Collin, a GCHQ analyst and chief puzzler, said 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 £50 note,” Collin said. “It might even have left him scratching his head – although we very much doubt it!”

The GCHQ said the answers to the first 11 puzzles “should give you 11 single words or names which you’ll need your very own Enigma simulator to decode”. So it’s perfect for people stuck indoors because of lockdown who are in dire need of a challenge.

For those who get stuck, the GCHQ has promised that they will release some tips and hints on their Twitter and Instagram channels to help people solve the Turing Challenge.