Researchers at Ben-Gurion University and Weizmann Institute of Science have found a new way of eavesdropping on conversations, called Lamphone. This is by capturing the light flickers made by a bulb, that’s caused by the vibrations from sound hitting the bulb’s surface. This method was previously seen, but need a malware injecting or high-end resources to perform. Here, researchers did with simple and accessible gadgets.

Eavesdropping from 80 Feet Away

Sharp shifts in technology-led many people to experience many smart things, but at the same time, there are also exposed to more cyber threats. Here’s a group of researchers from Ben-Gurion University of the Negev and Weizmann Institute of Science, tried to scoop out the conversations and other sounds from a distance of 25 meters (80 feet)!

The research published this week revolves around the concept that, objects vibrate when a sound hits on their surface. And in case of a bulb, these vibrate in turn cause the light to flicker, slightly at least.

Researchers cashed this theory, as they tried reading out those light flickers from a distance through basic objects like a telescope, a recording algorithm, and a computer to tune back the received data into their original form, sound.

Limitations of the Technique

Calling this technique as Lamphone, any adversary can try doing the same to trace one’s sounds. But here’s a catch, this method works only there’s no object obstructing the viewing path and the type and thickness of light bulb’s glass too can affect the reading.

Further, the object producing sound, whether people talking of some speaker, should be closer to the light bulb to reflect sound properly on their surface.

Though other methods in the past like Gyrophone and Visual Microphone did the same, they either need malware to be shared with the victim or heavy resources to do. But the Lamphone technique is done with simple means and can record from farther distances if the gadgets are upgraded. Researchers will be presenting this method at Black Hat Security Conference, a virtual event scheduled from 1st to 6th if August 2020.

Via: ZDNet


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