Beginner's Programming Challenge 18
Hi all, as I am the winner of Beginner's Programming Challenge 17 I have the honour of bringing to you Beginner's Programming Challenge 18.
This time the challenge involves some basic cryptography. You must implement the Vigenère cipher in a programming language of your choice. Your program must prompt the user for a plaintext (the message) and a key (the password) and it should output the corresponding cyphertext (the encrypted message). For the sake of simplicity both the message and the key must contain only uppercase letters of the English alphabet.
For bonus points your program should also be able to decrypt a message given a cyphertext and a key.
This is a beginner's challenge, so the source code shouldn't be hard to read. Also please include plenty of comments.
Best of luck to all.
Last edited by roccivic; January 18th, 2011 at 10:08 PM.