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, ...

J K Rowling’s The Hallmarked Man features the Pigpen Cipher, a centuries-old code once used by Freemasons and revolutionaries ...

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 ...

What does it mean? Well, intrepid Business Insider readers realized quickly it was a substitution cypher, something that is pretty simple to solve. In this case, c in the cypher is t, and d in the ...

The Soviet VIC cipher used in the early 1950s, long known for being complex and secure, may not be as impossible to crack as initially assumed. According to a recent article cracking the infamous ...