Hi guys
I was thinking today about how to design a lock that deters any attempt to pick it. I'm not talking about something mechanically perfect that is impossible to pick (as that does not exist to my knowledge), but rather something that isn't worth the effort. Bear in mind I'm a complete newbie so feel free to shoot this down if it's a stupid idea (which it probably is):
A 7-pin pin tumbler lock in a secure door, but the 7th pin isn't actually a part of the lock's operation but instead triggers an alarm if raised. The key would be either flat at the tip with standard bitting over the rest of it (so that when you slide it in it doesn't manipulate the last pin to a great extent), or it would be short enough to not reach the 7th pin. So in essence the inserted key would manipulate all the pins as it should without touching the 7th. As a picking attempt involves raising all the pins to feel for the one that is binding, the picker would inevitably raise the false pin at the back and trigger the alarm.
I imagine the problem with this (if it's possible to do in the first place) is that every one of these locks would have to be custom made with slightly different specs, otherwise everyone will know about it and create custom tools to defeat it. Apart from that, is it theoretically possible to do?