You can make a message secret in countless different ways. One common way is to use a substitution cipher, in which one letter is substituted for another. Another is to employ a transposition cipher, ...

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 ...

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 ...

Threat actors in the phishing business have adopted a new technique to obfuscate the source code for the forged page by using a custom web font to implement a substitution cipher that looks like ...

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 ...

Hannah handed me a piece of paper with the following string of letters. “Each letter stands for another one,” said Hannah. “Ooh, a substitution cipher!” I thought. But I was stumped. “Is this just one ...

This morning, the NSA Careers Twitter account posted what looked like a series of nonsense letters: tpfccdlfdtte pcaccplircdt dklpcfrp?qeiq lhpqlipqeodf gpwafopwprti izxndkiqpkii krirrifcapnc ...