Not many real Confederate Army Cipher Disks survived and there are only five known to exist today. Two of these are in the hands of private collectors, one is part of the collection of the Smithsonian Institute and two are at the Museum of the Confederacy in Richmond (Virginia, USA).
The Disks could be used as simple substitution cipher by setting the wheels at a known alignment, such as using setting the inner wheel letter A with the outer wheel letter D as shown in the photo of the Confederate Cipher above, but this would have been quite easy to decode. Instead the wheels were used in more elaborate fashions based on the Vigenére method.
The Vigenére Cipher is a 16th century encryption method that has been the basis for most cipher techniques since that time. It works by applying a series of different substitution Ciphers on the plain text, based on the letters of a so-called keyword. The letters of the keyword shift the relationship of the actual text to the encoded text on wheels or a chart. In this case, it determines how many places the inner disc should be shifted in relation to the outer disk
Here is one example where we will use a keyword and shift the wheels after each letter to get an entirely new relationship of the wheels.
Suppose that the plain text to be encrypted is: ATTACKATDAWN
The person sending the message chooses a keyword or phrase and repeats it until it matches the length of the plaintext; for example, a keyword sometimes used in the south was CONFEDERATE.
On the inner wheel, the letter A becomes our pointer. To set the wheel up to encode the first letter, align the letter A on inner wheel with the first letter of the keyword, which is “C”.
Now we have the wheels set to encode the first letter of our message. Throughout the process we will use the inner wheel as the plain text and the outer wheel as the encoded text.
Since the first letter of our message is A, the encoded letter is C. (“A” is read on inner wheel and “C” is read on outer wheel.)
Now change the alignment of the wheels to so we can encode the second letter. The A from the inner wheel now must align with the “O” on the outer wheel since O is the second letter of our Keyword. Now that the wheels are set we are ready to encode the second letter of our message (T). Find the T on the inner wheel and you will see that the encoded letter to use from the outer wheel is H.
Now change the wheel alignment to set up to encode our 3 letter, another T.
Align the letter A from the inner wheel to the 3rd letter of our keyword , CONFEDERATE, which is N. Now we can encode the T by finding the “T” on the inner wheel and looking at the outer wheel we see the letter “G” as our encrypted letter.
If you repeat this process for each letter of our message your will generate the cipher message: CHGF GNEK WAAP
Note how the message is arranged in groups of 4 letters so as to not give away word length. It makes it a little more difficult to decode, but makes the message more secure. Groups of 4 or sometimes 5 letters were used.
Plaintext: ATTA CKAT DAWN
Key: CONF EDER ATEC
Ciphertext: CHGF GNEK WAAP
On the reverse side of the page I have included an encoded message for you to decipher.
It is important to understand each of the puzzles and props in your Escape Room to ensure you can utilize their full potential. With this in mind I have created an instructional series to help familiarize yourself with our Cipher Wheels and Encryption Machines.
Links to how to use our other Ciphers: