John Croft, who has died aged 103, was a codebreaker at Bletchley Park in Buckinghamshire during the second world war, and subsequently in London, where he worked on Soviet cipher systems used to send secret messages to European communist parties and sympathisers.
Croft was studying history as an undergraduate at Christ Church, Oxford, in 1942 when his tutor asked if he might be interested in intelligence work. “The prospect, whatever that involved, seemed enticing and I gratefully accepted the opportunity,” he later recalled. He was subsequently interviewed in Oxford by Col John Tiltman, Bletchley Park’s chief codebreaker. “Tiltman himself appeared to me almost the parody of a regular army officer, with toothbrush moustache and rather clipped speech; as I was to discover later, he was a man of outstanding skill and experience.”
