This article has a few issues. First, you spend the first half of the article explaining a signature scheme that isn't based on cryptography. It isn't really c

This article has a few issues. First, you spend the first half of the article explaining a signature scheme that isn't based on cryptography. It isn't really clear what that part of the article is actually about. > "Signed by John" <- John encrypts this line using his private key This isn't how message signing works. It has all the problems you described in the first part, before you introduced asymmetric encryption.