Select Code to Download

A message encrypted with this system can be broken easily in only 2 ke
+y periods

("case" ^ "hook") eq ("gone" ^ "lark")

What if you don't know the key length to start with? Some well-chosen 
+shifts and xors expose the redundancy in the N*(N-1) period, allowing
+ it to be attacked with frequency analysis as though it had a length 
+of only N+(N-1).