Researchers Discover Computer Screens Emit Sounds that Reveal Data

Using a computer version of synesthesia, researchers demonstrate a new vulnerability present in most flat-panel monitors that can reveal contents to a remote party. For some people with the neurological condition, synesthesia can be a lovely thing when the sounds they hear also produce colors. But computer scientists from Tel Aviv University, the University of Pennsylvania and the University of Michigan have discovered a computer version of synesthesia that allows them to determine what’s being displayed on a monitor by listening to sounds emitted by the monitor. As you might suspect, those sounds are very faint and not easily detected by human hearing. But they are there as tiny high-pitched tones produced by a monitor’s power supply in response to the varying demands of the screen display. But special equipment isn’t required to exploit the vulnerability that’s produced by this characteristic of most monitors.