Alberti Cipher Disk
Here is an explaination of the Alberti cipher.
The Alberti Cipher Disk was one of the first polyalphabetic encryption system.
It was invented by Leon Battista Alberti, a famous italian philosopher and architect in about 1467.
In this encryption system there are two different rotating disks.
Alberti used two different alphabets located on concentric rings - this means one ring is inside of or on top of another. By lining up two different letters, one from each ring, he could make a simple substitution alphabet in which he could create a cipher.
For example, if he aligned the A on the outer ring with the G on the inner ring, this would make the following substitution alphabet used to encrypt a message:
OUTER RING: ABCDEFGHIJKLMNOPQRSTUVWXYZ
INNER RING: TDVHARSZCPEWIXGUKMBLYFJONQ*
From there, he could encrypt his message and send it to someone who knew the secret to revealing the message.
*=Alphabet used in the script.
Here you can try the Alberti Cipher Disk script.