Caesar's Cipher

What is Caesar's Cipher?

Caesar's Cipher is a way to keep a message secret by shifting the letters of the alphabet. Julius Caesar used it to send hidden messages a long time ago!

Caesar's Cipher is easy to learn and a fun way to hide messages. Today, it helps teach how encryption works.

How It Works

1. Pick a number: Choose a number between 1 and 25. This is how many spaces each letter will move.
2. Shift the letters: Move every letter in the message forward by that number. For example, if the number is 3:
   • A becomes D
   • B becomes E
   • C becomes F
3. Wrap around: When you go past "Z", start again at "A". So "Z" becomes "C" if you shift by 3.

Example

Let's shift the word "HELLO" by 2:

• H becomes J
• E becomes G
• L becomes N
• L becomes N
• O becomes Q

The secret message is "JGNNQ".

How to Decode

To decode the message, just move the letters backward by the same number!

Learn More

Want to master Caesar's cipher? Check out these easy-to-follow resources:

• Khan Academy: Caesar Cipher

  Watch simple videos that break down the cipher step-by-step.

• Simon Singh's Caesar Shift

  Try an interactive tool and learn about the cipher's history.

• Interactive Math: Caesar Cipher

  Practice with hands-on examples and clear explanations.

These guides cover everything you need to know about Caesar's cipher. They're fun, easy to follow, and packed with useful information.

Caesar's cipher is great for learning, but it's not safe for real secrets. It's just the beginning of the amazing world of codes!