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 ...

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 Voynich manuscript has long been shorthand for the unsolved and the unknowable, a late medieval codex filled with looping ...

Researchers have used state-of-the-art machine translation software — and some old-fashioned hunches — to crack the code used by a secret society in Germany three centuries ago. The results shed light ...

The FBI today challenged anyone in the online community to break a cipher code on its site. The code was created by FBI cryptanalysts. The bureau invited hackers to a similar code-cracking challenge ...

Sam Blake, an Australian mathematician, first learned of the Zodiac Killer’s unsolved ciphers — a series of encrypted messages — from a documentary in the 1990s. His interest marginally increased in ...