Create Your Own Secret Code!

For kids

Want to send secret messages to your friends? Learn how to make your own code! We'll use a simple substitution code where each letter becomes a different letter. It's fun and easy!

What You'll Need

• Paper
• Pencil or Pen

Making Your Code

Let's create a substitution code. This means each letter in the alphabet will be replaced by a different letter. This is how you make it:

1. Write out the alphabet on a piece of paper.
2. Choose a new letter for each letter of the alphabet. For example: A could become D, B could become E, C could become F, and so on.
3. Write your new code alphabet below the regular alphabet.
4. Write a secret message using your new code.
5. Give your friend the new code alphabet and the secret message.
6. Have your friend use the code to decode the message!

Example Code

Here's an example of a simple code:

Original:  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Code:      D E F G H I J K L M N O P Q R S T U V W X Y Z A B C

If you wanted to write "HELLO" using this code, it would become "KHOOR".

Decoding a Message

To decode a message, you need to know the secret code. Then, for each letter in the coded message, find the matching letter in the original alphabet.

Let's decode "KHOOR" using the example code above:

• K becomes H
• H becomes E
• O becomes L
• O becomes L
• R becomes O

So, "KHOOR" becomes "HELLO".

Try This Next!

• Make your own, more complicated code!
• Use numbers or symbols instead of letters.
• Try writing a secret message to your parents!

Have fun creating and cracking codes! Keep your messages secret and enjoy the fun of sending and receiving coded messages!