Modern spy technology continues to improve, demonstrating advances that were previously unimaginable. Even a regular HDMI cable can violate a person’s privacy, acting as a source of information leakage.
Image source: x.com/Psalteric
The TempestSDR system reveals such capabilities – it is capable of intercepting the signal coming from an HDMI cable and almost completely recreating the image on another screen. This turned out to be possible due to the fact that the cable creates an electromagnetic field, the parameters of which can be read. The output picture quality is low, but artificial intelligence can improve it. It makes the text readable and the image clearer. The DeepTempest neural network developed for these purposes helps reduce the number of errors by more than 60%.
DeepTempest significantly improves image quality and reduces the number of errors in text recognition, but the picture remains unclear. To intercept, you need to be very close to the cable – in fact, close enough to see the screen whose signal the potential attacker is trying to read. Sitting in a van across the street, it will be extremely difficult to see anything, even if the cable has very poor shielding.
Your HDMI cable can leak what’s on your screen watch the laptop on the left. it reconstructs the video playing on the monitor beside it from radio signals leaking out of the HDMI connection this is TempestSDR. an antenna picks up the leakage, a HackRF radio captures it, and software turns it back into an image researchers took this further with Deep-TEMPEST, using AI to make recovered images and text easier to read. this clip shows the original technique quality depends on shielding, distance and interference. the picture is imperfect, but recognizable content still gets through a wired connection can still leave a wireless trace
— Psalter (@Psalteric) November 8, 2026
The DeepTempest system was developed by Federico Larroca from the University of the Republic in Montevideo (Uruguay). When used to capture text, it reconstructs content with errors in approximately 30% of characters—the technology exhibits an error rate 60% lower than the most advanced attack methods previously available. The term Tempest in such systems did not appear by chance: this is the code name adopted by the US NSA to denote surveillance through electromagnetic leaks, as well as measures to counter it.
The most effective way to protect against such attacks is to use high-quality cables with electromagnetic shielding. It is necessary not only to ensure high quality sound and image, but also to protect against leaks.
If you notice an error, select it with the mouse and press CTRL+ENTER.
