Caesar Cipher

Note that in Sage webpages, you must evaluate the cells in order for the demonstration to work.

Here we define an alphabet:


Here we ‘encode’ our message in the alphabet:


Now we define the Shift Cryptosystem (i.e. Caesar cipher):


Now we can create a ciphertext out of our plaintext and a key. Here we use key=1, i.e. a shift by 1 character:


Now we can decipher using the same key:


Here’s a sandbox for you to play with: