You could do worse than to confuse the meanings of "code" and "cipher"—even cryptographers sometime use the terms as though they had the same meaning. There is, however, a definite distinction between ...

In Part I, you broke a simple cipher. Now try creating a more complex cipher. Cut out the NOVA Decoder Ring and NOVA Cipher Code Ring and the window marked INDEX. You are now going to put this simple ...

In the context of cryptography, the un-transformed message is known as plaintext, the transformation is known as encryption and the transformed message is known as ciphertext. The encryption process ...

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 ...

The arena of creating secure environments in the hardware and software industries is somewhat shrouded in mystery and misunderstanding. Certainly, some types of ciphers are relatively straightforward ...