Title: Spy codes and ciphers
Description: "Discusses different methods of secret communications used by spies, such as Morse code, the Enigma machine, the Najavo language, and digital steganography, and includes career information"--Provided by publisher.
Subjects: Cryptography, Ciphers, Spies, Juvenile literature, Espionage, Spies, juvenile literature, Espionage, juvenile literature