The Codebreakers: The Comprehensive History of Secret Communication from ... - David Kahn - Google Books

https://books.google.de/books?id=3S8rhOEmDIIC&pg=PA550#v=onepage

The magnificent, unrivaled history of codes and ciphers -- how they're made, how they're broken, and the many and fascinating roles they've played since the dawn of civilization in war, business, diplomacy, and espionage -- updated with a new chapter on…