Today is the #idesofmarch, marking Julius Caesar's assassination and a turning point in Roman history. But, what does this have to do with #encryption, you ask?
Caesar used to communicate privately by encrypting his correspondence with what came to be called the #caesarcipher.
This simple and widely known encryption technique is a substitution cipher in which each letter in plaintext is replaced by another letter following a fix position further up or down the alphabet.
This modest form of #encryption required no mathematics, and it could be done by finger-counting.
I'm trying to get my head round HTTP Signatures as they're used extensively in the Fediverse. Conceptually, they're relatively straightforward. You send me a normal HTTP request. For example, you want to POST something to https://example.com/data You send me these headers: POST /data Host: example.com Date: Sa…