David Kahn spent eight years researching and writing this book, including a year in the German military archives. He holds a Ph.D. in history from Oxford and is also the author of the acclaimed best-seller The Codebreakers: The Story of Secret Writing. He lives in Great Neck, New York.

David Kahn spent eight years researching and writing this book, including a year in the German military archives. He holds a Ph.D. in history from Oxford and is also the author of the acclaimed best-seller The Codebreakers: The Story of Secret Writing. He lives in Great Neck, New York.

David Kahn spent eight years researching and writing this book, including a year in the German military archives. He holds a Ph.D. in history from Oxford and is also the author of the acclaimed best-seller The Codebreakers: The Story of Secret Writing. He lives in Great Neck, New York.