How does one crack the world’s most famous code? The breakthroughs on Kryptos provide a guided tour through the cat and mouse game between code makers and code breakers that has defined information ...

The 35-year-old saga of Kryptos, an enigmatic sculpture containing four encrypted messages outside the CIA headquarters, just ...

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 ...

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, ...

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 ...