Question :

Prepare a  multithreaded code breaking program. You have been provided 3 files that contain text that have been  encrypted using a Caeser cypher scheme.

The task is to figure out the  2 keys used in the scheme. The encryption algorithm looks like:

   character = character + key1;

   character = character ^ key2; (^ = xor) and encrypts  the  characters 1 by 1.

Your code requires to decrypt the 3 text files by guessing  the 2 keys. You will know you have found the correct keys when you find  in the text  the string "Dr-Ronald-Marsh".

To get you started,  the  file HW10-A.dat uses the  keys (1, 6) and the file HW10-B.dat uses the keys (25, 44). The  file HW10-C  uses keys > 0 && < 100.