Now, attackers can use bulbs to spy on you (theoretically)
What's the story
If you are planning on discussing private matters with someone, better start with keeping all the windows and doors shut. The precaution is peculiar, especially when no one is lurking outside your door, but necessary in light of a new 'lamphone' hack that enables attackers to eavesdrop on conversations using simple light bulbs. Here is more about it.
Attack
The way to spy through bulbs
Discovered by researchers at Ben-Gurion University, the lamphone hack allows attackers to capture sounds in a room by simply looking at the vibrations they create on the surface of light bulb[s]. Basically, the vibrations caused by the sound waves affect the bulb in such a way that its light output witnesses minute changes, which can then be measured to interpret what is being said.
Demo
Content of conversations, music can be captured
In a demo, the researchers showcased that their trick could easily give away content of conversations, even the music being played in a room. "Any sound in the room can be recovered...with no requirement to hack anything and no device in the room," said Ben Nassi, a researcher at Ben-Gurion. "You just need line of sight to a hanging bulb, and this is it."
Details
Telescope, laptop, and a special sensor used for the hack
For their demo, the researchers used $1,000-worth equipment, mainly a telescope, a laptop, and an electro-optical sensor that converts light, or a change in light, into an electrical signal. The sensor was integrated with the telescope and the whole unit was placed 80-feet away from the target's bulb. Then, as the target spoke in their room, the telescope captured light changes as electrical signals.
Information
Simultaneously, the electrical signals were processed
As the target continued their conversation, the telescope went on to record the electric signals, which were simultaneously fed into an analog-to-digital converter to create perceivable digital information. Finally, the readings were processed on a laptop to filter out the noise and reconstruct the sounds.
Limitations
But, the trick could have some limitations
While the technique was able to produce sounds with high accuracy, there could be certain limitations of the hack. For instance, it is not clear if a fixed bulb would generate enough vibrational changes to be decoded. The team used a hanging light bulb. Secondly, the target speaker was also set to a very high volume, which means normal/low pitch conversations could go uncaptured.
Information
More details to be shared in August
The researchers plan to share more about lamphone at the upcoming Black Hat security conference, but their work clearly shows that we have to be more careful in maintaining our privacy because the hackers are growing smarter than ever as we speak.