Password Key for Mac

From Desert Penguin:

Password Key was designed to provide a limited amount of security to your Macintosh system with emphasis on "security without modification" in its processes. Even though it offers a fairly high level of security to the average "looker", it does not in any way, affect either the hardware configuration, system software, or any of your files. When used properly, Password Key should provide you with at least the knowledge of "illegal attempts" to enter your system, and at best, with a system that is left alone with its integrity kept complete.