Lamphone: New technique for eavesdropping on conversations via lamp: Lamps visible from windows, or "Lamphone", are the new eavesdropping after "wiretaps" and hacking mobile phone
Spying techniques have skyrocketed in recent years, with new ways of monitoring being added to the list every year.
Researchers fromBen-Gurion Universityof the Negev and theWeizmann Institute of Scienceunveiled a new technique long-distance eavesdropping, dubbed the “Lamphone.” They said it allows anyone to listen to the sounds of a room with a laptop and equipment costing less than $1,000, such as a telescope and a $400 optoelectronic sensor.
The lampphone observes the tiny vibrations that sound causes on the glass surface of the lamp. By measuring the very small changes in light caused by these vibrations, researchers have shown that a spy can pick up sound clearly enough to distinguish conversations or pieces of music.
“Every sound in the room can be recovered without necessarily breaking anything and without the presence of any devices in the room,” said Ben Nassi, a security researcher at Ben-Gurion, who developed the technique with Yaron Pirutin and Boris Zadov. They also plan to present their findings on the lampone at theBlack Hatin August.
«You just need a point of visibility for the pendant lamp, and that's it.»
In their experiments, they set up an array of telescopes about 80 feet away from a targeted desk lamp, and placed the lens of each telescope in front of a Thorlabs PDA100A2 opto-electrical They sensor.then used ananalog-to-digitalto convert the sensor’s electrical signals into digital information. While playing music and recording conversations from the remote room, they uploaded the information they retrieved via the Lamphone to a laptop, which analyzed the data.
The researchers also found that the vibrations of the lamp from the sounds were recorded as measurable changes in light, which were detected by the sensor through each telescope. After processing the signal through noise-filtering software, they were able to reconstruct the recordings of the sounds taken by the lampphone with considerable accuracy.
For example, they showed they could reproduce an audio clip of Donald Trump speaking well enough to be verified byCloud Speech API’s Google . They also reconstructed a recording of the Beatles ’ “ Let it Be ” clearly enough for Shazam to instantly recognize it .
The lampphone technique certainly has some limitations, such as the fact that it is not yet clear whether it works with a floor lamp or a ceiling light. Also, in the material they used for their tests, the sound was quite a bit louder than the average human conversation. Of course, the team emphasized that they used relatively cheap equipment and that they could have upgraded it to experiment with lower-volume conversations. LED bulbs also offer a signal-to-noise ratio about 6.3 times higher than a simple incandescent bulb, and 70 times higher than a fluorescent one.
Regardless of these inaccuracies, Stanford computer scientist and cryptographer Dan Boneh argues that the researchers' lampone technique represents an important, and potentially practical, new form of "side channel" attacks, attacks that exploit audio .
«It's a beautiful application of side channels. Even if it requires a pendant lamp and high intensity, it's still extremely interesting. And it's the first time this has been shown to be possible. Attacks are only getting better, and future research will only make them better..»
The team of researchers, led by BGU's Yuval Elovici and Adi Shamir , the co-founder of the RSA encryption system , is not the first to show that unexpected sound phenomena can lead to eavesdropping, such as the lampphone.
Researchers have known for years that if you shine a laser through the window of your target, you'll pick up the sounds inside. Even the gyroscope of an exposed smartphone can collect sounds.
The previous, closest to Lamphone, technique was by researchers at MIT, Adobe, and Microsoft in 2014, called the “virtual microphone.” This team analyzed video, recorded by telescopes, of an object receiving vibrations, such as a plant. This way, they were able to recover speech or excerpts of music.
However, Nassi emphasizes that this technique requires analyzing the video after recording it, while with the lampphone you get immediate results. Since the lamp is a light source, the sensor can extract the vibrations with much simpler optical data. Which makes it much more practical.
"Since you can use it in real time, you can also respond immediately instead of missing the opportunity. We want to increase vigilance for these types of attacks. We are not on the side of producing these kinds of tools," Nassi said.
It may seem unlikely that you'll be attacked with techniques similar to the lampphone, but it's best to be safe. Simply cover hanging lamps, or close your curtains, to block visibility.
