This project is an extension of the CS First Unplugged activity Send a Secret Message (g.co/csfirst/unplugged). Use the left and right arrows to set your cipher key and then click the Encrypt or Decrypt button to input a message to encrypt or decrypt. To encrypt a message, the program finds each of your letters on the outside ring and replaces it with the matching letter on the inside ring. When you decrypt a message, it does the opposite.