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 ...

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 ...

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 ...