The UK’s intelligence, security and cyber agency (CGHQ) has released its “toughest puzzle ever” in honour of Alan Turing appearing on the new £50 note.

The Alan Turing £50 banknote will be issued for the first time on June 23 2021 to coincide with his birthday, the Bank of England has confirmed.

The announcement was made as the Bank unveiled the design of the new polymer £50 note, which contains advanced security features.

The note will join the Sir Winston Churchill £5, the Jane Austen £10 and the JMW Turner £20, meaning all Bank of England notes will be available in polymer, which lasts longer than paper.

Mr Turing was a pioneer of modern computing and hugely instrumental in breaking the German Naval Enigma cipher in 1942, at Bletchley Park – GCHQ’s wartime home.

Director of the cyber and intelligence agency Jeremy Fleming described him becoming the first gay man to appear on a banknote as confirming his status as “one of the most iconic LGBT+ figures in the world”.

Mr 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 persecuted 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.”

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 Mr Turing to break Enigma-enciphered messages.

But all are said to be extremely difficult, with experts saying the challenge should take even the most experienced puzzlers seven hours, according to MailOnline. 

Mr Turing’s great-nephew, James Turing, described the puzzle as a “wonderful tribute” which his family would be attempting to complete themselves.

See if you can crack the code here.

Who was Alan Turing?

Basingstoke Gazette: The Bank of England revealed the note’s design featuring the scientist and mathematician on Thursday. (PA)The Bank of England revealed the note’s design featuring the scientist and mathematician on Thursday. (PA)

Born on June 23 1912, Mr Turing studied mathematics at King’s College, University of Cambridge, gaining a first-class honours degree in 1934. He was elected a Fellow of the College.

In 1936 his work On Computable Numbers is seen as giving birth to the idea of how computers could operate.

His “Turing test” also examined the behaviour necessary for a machine to be considered intelligent – the foundation for artificial intelligence.

Perhaps Mr Turing’s best-known achievement was his role in cracking the Enigma code.

It has been said this helped to shorten the length of the Second World War by at least two years – saving millions of lives.