How to Make a Cipher Wheel

Sending and receiving secret messages is great fun for kids. Here is an easy way to make a secret code device called a cipher wheel.

Difficulty:

Easy

Instructions

Things You'll Need

• Sheet of paper (index card stock is even better if you have a sheet available)
• Compass to draw circles
• Scissors
• 2 paper fasteners
• Protractor to mark off degrees
• Pencil or pen

1. These directions are for a set of two identical cipher wheels, because both you and the person you are corresponding with will need a copy of the code. Use the compass to draw four circles. Make two circles with a diameter of 4 inches and two circles with a diameter 4 1/2 inches. If you would like to make them larger, you can. Just make sure that there is about half an inch difference in the diameter of the circles.

2. Cut out the circles and fastener them together at their centers with the paper fasteners.

3. 

   Mark off 26 sections around the outside of the circles. If you want to use the protractor to help you with the spacing, each section will be approximately 14 degrees (13.8 degrees to be exact).

4. 

   Write the alphabet from A to Z on the outside circle.

5. 

   Write all the letters of the alphabet in random order on the inner circle. Make sure both cipher wheels are identical!

6. To use your cipher wheel, begin your secret message with two key letters. The first letter will be one on the outer circle, and the second will be the matching letter on the inner wheel. Keep the wheel in this position while you translate your message. The recipient of the message should know ahead of time that the first two letters of the message will be the "key" used to set the wheel to the same position the sender used.

Tips & Warnings

• Try using something other than letters on your inner wheel. You could make up your own code of shapes and squiggles, adding another layer of complexity to your messages. Just make sure you use a few ordinary letters in your own code so that you can refer to it in your initial two-letter key at the beginning of your message.