It’s not exactly new. It’s known as Van Eck Phreaking. There are open-source projects such as TempestSDR that uses software defined radio dongles (such as RTL-SDR and AirSpy) to reconstruct a remote screen just by listening to its radio interferences.
I once listened to the radio noises emanated from my HDMI connection between my laptop and my LCD screen using a Baofeng UV-5R tuned in UHF frequencies. I could tune it from the street, dozens of meters away from the computer desk. HDMI is very noisy, even noisier than VGA. Even the shortest HDMI cable serves as an antenna for propagating such interference.
just curious but from your experience is Displayport just as bad or is it worse than HDMI for this exploit?
I didn’t test displayport, but IIRC it’s digital, like HDMI is. So, my guess is that Displayport also emanates lots of EM interferences. The very sharp nature of squarey digital waves (in contrast to a sinusoidal wave from analog) decomposes into high-frequency interferences (because a square wave always has high frequency components, as observed through FFT). That’s what causes UHF interference.
I’m sorry, but even if this isn’t new, I find it completely insane. Like, mind-blowing. Damn.
