Even with a key you can drown out the signal by blasting enough RF waves at the receiver or area. I’ve heard a Growler pilot describe what they do as shining a spot light in your face to blind you.
You can, if the spot light is strong enough, and the person in question isn't floating in deep space. Just keep adding power until the light reflected by the person's surroundings is strong enough to blind them.
> Not to mention the tricks they use to make RF signals directional to both send and receive.
Makes me wonder if there's an RF equivalent of getting permanently blinded by laser light scattering off random objects in your line of sight.
Current areas where jamming is being detecting.
Incidentally, there has been a recent escalation in this: over Iraq commercial airline pilots have been reporting increasingly successful GPS spoofing, with GPS positions being shifted by tens or hundreds of nm, the clock being shifted, etc. In some cases this has exposed bugs in aircraft software where it has not successfully recovered the GPS position even after leaving the affected area, leaving them with degraded navigation all the way to the destination.
This is not as dire as it might sound, as there are plenty of other ways for an aircraft to determine its position, though it certainly reduces the margins for error in some cases. But it’s interesting because such spoofing should be extremely difficult to carry out successfully, especially on a moving target like an airliner.
In that particular instance, but:
* https://en.wikipedia.org/wiki/Electronic-warfare_aircraft
Waiting for drones: