The head of intelligence agency GCHQ has paid tribute to World War II codebreaker Alan Turing, saying that the "cost of intolerance was a loss to the nation" during centenary celebrations of the mathematician's birth.
Spy chief Iain Lobban described Turing as "one of the great minds of the 20th century" whose breakthroughs have laid the foundations of the modern information age". Turing worked at the Government Code and Cypher School at Bletchley Park - the forerunner of GCHQ - where he devised the techniques which cracked the German Enigma code.
But despite his achievements he was found guilty of "gross indecency" in 1952, a conviction for the-then illegal act of homosexual sex. Turing chose to be chemically castrated by being injected with female hormones rather than go to prison. Two years after his conviction he died of cyanide poisoning, a verdict recorded as suicide at his inquest. Although his mother and other academics have maintained his death was accidental, many have argued he took the poison deliberately to end the persecution he was suffering for being homosexual.