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 ...

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 ...

Ever since writing has existed, people have wanted to send secret messages to one another--and others have wanted to intercept and read them. This is the second installment of a blog series taking you ...

Today we’re going to talk about how to keep information secret, and this isn’t a new goal. We’re going to walk you through some common encryption techniques such as the Advanced Encryption Standard ...

Cryptographic algorithms lie at the heart of modern information security, and substitution box (S‐box) design is a critical component in achieving robust encryption. S‐boxes provide the nonlinearity ...