A letter can say one thing and mean something completely different.For centuries, that possibility mattered enormously. A messenger could be stopped. A ship car ...

In cryptology, the discipline concerned with the study of cryptographic algorithms, a cipher is an algorithm for encrypting and decrypting data. Transposition ciphers keep all the original bits of ...

Throughout human history, the desire to communicate in secret has driven some of the most brilliant minds to create increasingly complex systems of hidden language. Generals encoded battle plans, ...

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 ...

The concluding words of Unsolved! are a call to action. Craig Bauer, a US mathematician and editor-in-chief of the journal Cryptologia, ends his hefty history of cryptography by noting that even as he ...