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 ...

In the context of cryptography, the un-transformed message is known as plaintext, the transformation is known as encryption and the transformed message is known as ciphertext. The encryption process ...

A few months ago, GeekDad's Challenge of the Week was a lovely cipher about famous novels beginnings. I enjoyed solving it and that reminded me of a time where I was teaching younger students (12 to ...