I had just recently taken a look at Code Lock and came up with the same conclusion, its challenge just a clever marketing campaighn which doesnt seem to have worked to well. The fact its zipped is rather obvious as it has zlib.dll which needs to be included with your application, for Visual Basic its next to useless as through various means someone can get a valid key and as you said decrypt the real exe. The only thing that slightly intrigued me about it was its use with .net, as I havent seen a .net protector with a encrypted section feature (there could be others I havent looked far and wide).