We use a simple method called the Vigenère cipher. It's like a secret code wheel for each letter!
Here's how it works: Your password gets repeated to be as long as your message. For each letter in your message, we look at the matching letter in the repeated password. That tells us how many spots to shift the message letter in the alphabet. For example, if the password letter is 'B' (which is 1), we shift the message letter by 1 place (A becomes B, B becomes C, etc.). We wrap around if we go past Z.
To decrypt, we do the same but shift backwards. Only the right password will give back the original message!
