Sometime we like to send a secret message to a friend that only they can understand.
So, how can we do that without going to trouble of creating our own secret language.
Actually, it is very simple.
By using a cipher wheel.
A cipher wheel replaces each letter of your message you want to send with another further along the alphabet.
It is also known as a cipher disk.
You kind of shift the alphabet, thus making it more like a shift cipher.
In this guide, I will be showing you how to make a paper cipher wheel and how you can use it to encrypt and decrypt any code.
It is time to keep your messages away from prying eyes.
Are you interested in finding out more about ciphers and codes?
The Codebreakers – The Story of Secret Writing book by David Kahn is what I would start with.
How to make a cipher wheel
Here are 6 material you will require in making a cipher wheel.
- Glue stick.
- Pen or pencil.
- Paper fastener or split pin.
- Cipher wheel template.
How to make a cipher wheel (using premade template)
- Print off the cipher wheel template.
- Then cut the wheels out and glue them onto the card with the glue stick.
- Carefully cut both of the cipher wheels out.
- Then write the alphabet in the outer boxes of both the small and large wheel.
- Using a sharp pencil, punch a hole through the center of both wheels.
- Then push the paper fastener through the smaller wheel and then through the larger wheel.
- Then open the split pin at the back so that the wheel are fastened together.
How to make a cipher wheel (from scratch)
- You need two concentric circles; one should be larger than the other.
- Then punch a hole in the middle of both and attach with a brass fastener so the inner wheel can move independent of the outer wheel.
- Then divide the entire circle into 26 sections. You can use a protractor to divide the circle into equal segments of about 13.8 degrees each.
- Then write the letters of the alphabet, in order, on both circles.
- Then decide on the key to use for encoding your message.
- Finally turn the inner wheel based on the key. To encrypt, look at the inner wheel and write down the letter that matches on the outer wheel.
How to encrypt using cipher wheel
First, choose a key to use.
To encode, simply align the circles so there is the same letter on the outer and on the inner circle.
Then move the inner circle the number of times given by the key.
You get your ciphertext using the inner circle.
That is, you replace each of your plaintext letter using the outer circle and encrypting it to the letter that corresponds to the inner circle.
Here is an example:
Thus, ciphertext: dbytgzt
How to decrypt using cipher wheel
Simply move the inner circle the number of times based on the key used to encode the message. Then, to decode look at the encrypted letter on the inner circle and write down the letter on the outer circle above it.
Do this for the entire ciphertext letters to get the original message at the end.
What are the variants of the cipher wheel
Cipher discs have many variations based on the basic design.
For example, instead of numbers only, one can use combinations of numbers on the outer disk with each combination corresponding to a letter.
To make it harder to break, use the advanced cipher disk with only the combinations of two numbers.
In your cipher disks, add additional symbols for commonly used combinations of letters like “ing”, “tion”, and “ed”.
You can also add symbols frequently to indicate “and” at the end of a word.
Are you interested in learning how to break codes?
The Elementary Cryptanalysis – A Mathematical Approach book by Abraham Sinkov is what I would recommend.