Gardner, Martin.
Codes, ciphers, and secret writing. - New York : Simon & Schuster, 1972. - 96 p. : ill.
Includes bibliographical references.
Explains in simple terms how to encode and decode messages in various ciphers, and gives formulas for invisible ink.
067165201X (lib. bdg.)
72082218
Cryptography.
Ciphers.
652
Codes, ciphers, and secret writing. - New York : Simon & Schuster, 1972. - 96 p. : ill.
Includes bibliographical references.
Explains in simple terms how to encode and decode messages in various ciphers, and gives formulas for invisible ink.
067165201X (lib. bdg.)
72082218
Cryptography.
Ciphers.
652