A friend and colleague introduced me to a 94-year-old gentleman with a rare tale to tell. John McCallister was recruited during World War II to be a US Army liaison officer at “Station X,” the UK’s highly secret codebreaking operation at Bletchley Park. Station X collected intercepted German radio messages, all encrypted with the supposedly-unbreakable Enigma cipher, and broke the encryption. The resulting data was distributed to a handful of senior UK and US military commanders.
At first, McCallister worked at Bletchley and learned about the codebreaking operation. He met Alan Turing, now recognized as a giant in computer science. Turing developed codebreaking machines at Bletchley, including the “bombe” (left). Then McCallister prepared for his own role: to handle and distribute the highly secret information to senior US military commanders.
Following the war, McCallister left the crypto world. After college and reserve service for the Korean War, he applied his mathematic skills to business accounting at General Electric and Zenith Electronics. He retired in 1984.