Resistor alarm key

Anyone try making a circuit to make use of a resistor "key" to act as a switch to disarm an alarm? I was considering using two voltage comparators to detect the insertion of a specific resistor, where it would have to be within a certain tolerance to trigger the output and disarm the security device. If I combined it with a momentary switch that will only allow one trigger attempt with a 20 second delay to lock out attempts at sweeping a potentiometer, would that be fairly foolproof? Thought maybe using a blade type fuse body with the resistor soldered in would serve as a key, with the fuse holder acting as the keyhole. Normal process would be to insert the fuse-key, then push the momentary switch to disable the alarm. If the momentary switch is pushed with the wrong resistor value in there, it wouldn't trigger, and an RC circuit would have to charge back up before a subsequent try. Sort of a simplistic version of the OEM resistor encoded ignition keys- might be interesting to try out; but wanted to see if it's be done and what the reliability might be. I was considering it for a motorcycle, so if it got rained on, it wouldn't be a good thing if the resistance dropped out of range as a result...

You could always get one of those waterproof fuse holders with the cap, so if it does rain, you won't have any water to deal with.

Yep, that ought to do it- Also, if I keep the tolerance wide enough on the allowed range, it should make sure it's not a problem. Using lower values would help too, but I'd like to keep the standby current draw at a minimum, since the bike battery doesn't have as much reserve capacity.