David Kahn is the author of the classic book The Codebreakers. When it was first published in 1967, the National Security Agency was concerned that the book might reveal sensitive secrets. Over the years, however, NSA changed from perceiving Kahn as “an enemy of the people” to depending on him as a popularizer of codebreaking. Join Peter and David Kahn as they discuss Kahn’s career, some of the greatest triumphs of American signals intelligence history, and the challenges facing today’s codebreakers.