UK premier Gordon Brown apologises to dead British computing pioneer

British prime minister Gordon Brown issued a posthumous apology for the 'appalling treatment' meted out to Alan Turing the British code-breaker who was chemically castrated for being gay.

The apology came as more than 30,000 people signed an online petition on the UK government web site calling on the government to recognise the 'tragic consequences of prejudice that brought about a man's life and career. Among those who signed the petition were writer Ian McEwan and scientist Richard Dawkins.

Turing's work during the war has been recognised as instrumental in turning the tide of war in favour of the allied forces.

Turing is considered as one of Britain's greatest mathematicians, who invented the code-breaking machine called the Bombe, that deciphered messages encoded by the German Enigma machines during World War II. Turing arrived at Bletchley Park the wartime headquarters of the GCCS on 4 September 1939, the day following UK's declaration of war on Germany and within weeks of his arrival he successfully demonstrated the Bombe that could help break Enigma coded messages faster than earlier machines. The Bombe was later enhanced to include mathematician Gordon Welchman's suggestion. The Truing-Welchman bombe as it came to be known became one of the primary tools to break the Enigma-protected German message traffic.

The bombe worked on Enigma messages with a suitable 'crib', which was a fragment of possible plaintext. For each possible setting of its rotors, which could have one of a possible setting of 1019 states or in case of U-boat Enigmas 1,022 states, the machine performed a chain of logical deductions using the crib. The bombe could detect a contradiction and rule out the setting. Most of the settings would lead to results that had to discarded leaving only a few for further investigation. Over 200 bombes were deployed y the end of the war.

After the war, Turing worked at the National Physical Laboratory on the ACE (Automatic Computing Engine). On 19 February 1946 he presented a paper on the detailed design of a stored-programme computer. Though Turing presented a feasible design for the computer, the project ran into procedural delays leaving him disillusioned. Turing left for Cambridge and the Pilot ACE was built in his absence; it ran its first programme in 1950.