Secrets With Ciphers and Codes,
by Joel Rothman
Introduces ten encoding methods using numbers, rearranged letters, colored squares and dots, and other systems. Provides a message to decipher with each method.
CiphersJuvenile literature
by Joel Rothman
Introduces ten encoding methods using numbers, rearranged letters, colored squares and dots, and other systems. Provides a message to decipher with each method.