Cryptography puts the “crypto” in cryptocurrency. It has existed much longer than our digital age and has evolved like languages over the centuries. One of the most famous uses was developed by Julius ...

Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

Here are the solutions to the GCHQ Challenge - codes considered so difficult to crack by the Cheltenham-based intelligence chiefs that they were planning to post clues on their website next month.

In 1854, Sir Charles Wheatstone invented the cipher known as "Playfair," named for his friend Lyon Playfair, first Baron Playfair of St. Andrews, who popularized and promoted the cipher. Its ...

NOVA scienceNOW's "Can Science Stop Crime" introduced you to Tadayoshi Kohno, a University of Washington computer scientist who's made it his mission to take over networked machines, identifying ...

Ars' own Julian Sanchez has deciphered a code embedded into the TV show Fringe. Bad Robot, the production company that created the Fox TV show, has been integrating puzzles and easter eggs into shows ...

Learn how to implement a classic substitution cipher in C! This step-by-step tutorial walks you through encoding and decoding messages by replacing each letter with another according to a fixed key. A ...