Complexity and chance
In one of the Miles Vorkosigan books, the main character has a device installed in his brain and a remote that can trigger a seizure - he needs that because otherwise he would get uncontrolled seizures, usually at moments of high stress (when that's the last thing he needs). One of his problems is having that remote triggered accidentally, so the doctors assure him they coded the connection - no random signal can trigger the seizure, only the remote. What are the possible dangers here? 1) Accidental signals that would match the frequency of the brain device, thus generating a false positive. How does one defend against this possibility? A small code of some sort is usually required for triggering the functionality - like the 4-digit code I have to enter when my Nokia cellphone locks the keys (to prevent me from accidentally dialing out when I keep the phone in my pocket). 2) Intentional signals from would-be hackers who want to trigger the device. In this case, one would need a muc