As civilizations rise and fall, many scripts and codes are written that eventually become lost to history and time. Some of what survives experts manage to decode, but others elude us and remain ...
1. Introduction -- 2. From Julius Caesar to simple substitution -- 3. Polyalphabetic systems -- 4. Jigsaw ciphers -- 5. Two-letter ciphers -- 6. Codes -- 7. Ciphers for spies -- 8. Producing random ...
"This book is a continuation of The history of codes and ciphers in the United States prior to World War I ... and is essentially volume 2 of Historical background of the Signal Security Agency, ...