An earlier study exposed how malign actors can hack Amazon Alexa and Apple Siri using laser light beams to send remote audible commands – but this is the first time it’s been demonstrated hackers can convert audio in real time without using external sources, such as malware.
A research paper produced by researchers at Israel’s University of Negev and Weizmann Institute of Science has revealed hackers can use an innovative technique to eavesdrop on private conversations by tracking vibrations in a lightbulb.
The technique, which the researchers dub “Lamphone”, works by intercepting vibrations in lightbulbs produced by changing air pressure created by sound. The researchers who captured the vibrations and turned them into audio claim they were able to listen to conversations from up to 25 meters away.
Terrifying Trifecta
The technique relies on three technologies – a telescope, which is placed in the field of view on the hanging bulb from a distance, an electro-optical sensor mounted on top of the telescope, and a sound recovery system to capture the sound and process it.
When a conversation takes place in a room, the sound creates fluctuations in the air pressure on the surface of the blub, causing it to vibrate – the analog electro-optical sensor then captures this vibration as an optical signal and processes it using an audio recovery algorithm.
In one test, the researchers were able to clearly pick up a pre-recorded speech by US President Donald Trump – in another, to see how and indeed whether the technique could pick up non-speech audio, the researchers listen to The Beatles’ famed Let It Be.
Because Lamphone only requires light vibration for capturing the audio, it doesn’t necessitate the victims’ direct engagement – one major drawback to the technique, however, is it requires a direct ‘line of sight’ to the lightbulb, within 25 meters. Nonetheless, employing telescopes with different lens diameters might allow the technique to function from farther away, it’s alleged.
Still, one way to counter a Lamphone attack would be to use weaker bulbs that emit less light, in the process limiting light captured by the sensor, according to the report. Another is by reducing the vibration with the help of a heavier bulb.
Sourse: sputniknews.com
