In this version a message M is encoded using a key K. This key is an n letter word that is transposed into the alphabet Key (A=1 , B=2, C=3) to produce the shift pattern. The message is then shifted using the Cesar cipher on this repeating key. You should code two solutions one where:
- The shift resets each time
- The shift carry on from where the last shift ended
Using this and a three letter key run some tests to work out which is the more secure when it comes to a brute force attack