Think of a word to encrypt. Encrypt it. Write it down and get a friend to decrypt it. The Caesar Cipher Code Wheel is one of the earliest known and simplest ciphers. It is a type of substitution cipher in which each letter is 'shifted' a certain number of places down the alphabet> For example, right shifting the inside ring by one, A would be encrypted to z, B would encrypt to a, C to b and so on. Restart. After a left shift of the inside ring by one, A encrypts to b, B to c etc. The English word is on the outside ring, and it does not move. It is necessary for both parties to have a key to decode the message (both would need a code wheel).
This was coded on request of Louth County Museum (Dundalk, Ireland). You can make a cardboard Caesar Cipher or use this online Scratch version. The cardboard version consists of two wheels held together with a brass paper clip. Go to the files folder of Facebook Group: Ready Steady Code - Scratch for Your Kids to locate and download the printable worksheet..
