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, ...

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 ...

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 ...

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 ...

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 ...

Encryption is an essential tool for protecting data—but the technology can be a bit confusing. This ebook explains what encryption is, how it works, and why it’s so important. From the ebook: ...