Shift Cipher Disk

This resource can be used to look at one method of encryption where letters of the alphabet are shifted by a number of characters to give a simple "shift cipher". The two disks need to be cut out and the smaller one mounted centrally on the larger one so that it freely rotates. The plain text outer letters can then be read off as coded letters from the corresponding inner disk of letters. All instructions are included on the resource sheet. Makes a fun activity whereby students can code up a plain text message and pass it on to a friend as a coded message along with the shift cipher +4, +23 or whatever who then decodes it. It also get over the idea of an encryption "key" being passed from one user to another to allow decryption.