Home-Made Security

A young woman's car stalled in our suburb today. She said that she was driving her boyfriend's car. He had added a switch and a push-button to the ignition, and she had forgotten how it went. Now logically, that might seem to make four binary options. But the switch and push-button were obviously anti-theft switches, and they were puzzlingly in full view. It wasn't one of the binary options. If the boyfriend knew anything about electronics, this could mean countless possibilities. OBSERVATION: I have designed many security circuits. Some simple ones may be impossible to crack. Not in all eternity would one think of how.

POSTSCRIPT: Think of a door lock as an example. Suppose it only opens if one stands on one leg and whistles Middle C. How long to guess the "code"? In the case of the car, suppose that the push-button itself requires a short binary code ...