The Lost Story of Alan Turing's "Delilah" Project

During World War II, Alan Turing led a secret voice-encryption project called "Delilah," a portable system designed to encrypt speech communications. Recently auctioned Bayley papers—Turing's handwritten notes and his assistant Donald Bayley's observations from 1943-1945—provide rare insight into Turing's work as an electrical engineer, revealing his transition from theoretical mathematics into practical circuit design and electronics.