Asymmetric and Symmetric Encryption
There are two main types of encryption that use certificates, and these are asymmetric and symmetric. We need to learn about each thoroughly. Let's start by understanding what encryption is. Please remember that you are taking plaintext and changing it into ciphertext.
Encryption Explained
Encryption is where we take plaintext that can be easily read and convert it into ciphertext that cannot be easily read:
- Substitution Cipher: Julius Caesar, who died in 44 BC, invented the first substitution cipher, where he moved each letter of the alphabet three places one way or another. This way, he could make his military plans unreadable if they had been intercepted. What he forgot about was that most people in those days could not read! This was called ROT 13, after the thirteen-letter rotation, and is now known as the Caesar cipher. For example, if I take the word
ECHO
and move each letter on thirteen places to the right in the alphabet...