A curious fact about hardware technologies that most people overlook is the emission of electromagnetic waves. When reminded of this, we generally don’t think of anything unusual, since everything powered by electricity generates this kind of unstable electromagnetic field. However, based on this principle, there is a fascinating type of attack: one that is undetectable and nearly impossible to defend against without proper equipment. The term Tempest refers to an espionage technique aimed at eavesdropping on electronic equipment via electromagnetic emanations; this concept also applies to sounds and vibrations. One of the most interesting aspects of this technique is the ability to snoop on video monitors by receiving the electromagnetic signals emitted by VGA/HDMI cables and other connectors. Now, imagine someone monitoring a company’s screens, deploying a Tempest setup that reads these waves.…