This also works with magnetic field frequencies, which go through faraday cages, and allegedly any hacked CPU can generate them by overloading certain parts at certain frequencies.
I’m not sure whether the average smartphone’s magnetometers can pick them up (the average smartphone can definitely emit them). But high-priority military computers need to be surrounded by massive iron blocks (“ferromagnetic shielding”) in order for an air gap smaller than 100 feet to actually be an air gap.
This also works with magnetic field frequencies, which go through faraday cages, and allegedly any hacked CPU can generate them by overloading certain parts at certain frequencies.
I’m not sure whether the average smartphone’s magnetometers can pick them up (the average smartphone can definitely emit them). But high-priority military computers need to be surrounded by massive iron blocks (“ferromagnetic shielding”) in order for an air gap smaller than 100 feet to actually be an air gap.