The list of methods of eavesdropping on more and more lines: we have seen wiretap eavesdropping devices attached to phone stethos, hacked smartphones, eavesdropping devices in places where many important people travel, even there are even “fiction” technology like lasers firing into building glass to hear conversations inside.
The list was just a little longer: That’s how a light bulb vibrates in a room and tells outside people what the conversation is about.
Researchers from Ben-Gurion University of Negev Region, Israel and from the Weizmann Science Institute have published a new remote eavesdropping technique called “lamphone”. They say the new way will allow anyone with a laptop, a number of technology devices worth less than $ 1,000 – including a telescope and a $ 400 photoelectric sensor – to work. can hear sound in a room from a distance of 25 meters; they were able to do that by observing the tiny vibrations, triggered by the effects of sound, on the glass surface of a light bulb.
By measuring changes in the light emitted (caused by vibrations caused by room sounds), the researchers showed that an observer could identify the content of the conversation, even identify it. played a piece of music …
Light bulbs also have “ears.”
“We can get any sound in the room without hacking something or placing the device inside. You just need to observe the light hanging in the room, that’s all“, Ben Nassi said. Nassi is a security researcher at Ben-Gurion University and is the developer of the technology and two other experts, Yaron Pirutin and Boriz Zadov; they plan to publish their findings at A security conference takes place this August.
In the experiment, the researchers placed a series of telescopes about 25 meters away from the target light bulb, and placed them in front of the Thorlabs PDA100A2 electro-sensing lens. They then use a converter to turn the electrical signal from the sensor into digital information. In the other room, recordings and some music are played continuously. The telescope records the data taken from the vibration of the light bulb hanging in the room and transmits it to a laptop for processing.
The team found that the vibrations on the bulb produced by the sound were loud enough for the sensor to pick up. After processing the data through noise filtering software, they were able to reproduce the sound emitted with incredible accuracy: the “translation” of the recording was clear enough for the speech recognition system Google’s Cloud Speech translates, and the track is clear enough for the Shazam song detection app to immediately recognize this as a song Let It Be by The Beatles.
Telescopes and photoelectric sensors can “hear” the conversation from a distance of 25 meters.
This technique still has certain limitations. In the experiment, the researchers used a ceiling-mounted light bulb, whether it was a fixed light bulb or a ceiling light that could produce enough vibration for the sensor to recognize the signal. The recording and music used in the test were also louder than a normal conversation, when the speaker of the transmitter was turned on to the maximum.
However, the team also said that photoelectric sensors and signal transmitters are cheap, more modern devices will be able to hear smaller conversations.
The limits remain, but computer scientist and cryptographer Dan Boneh from Stanford University maintains that the new technique shows an unprecedented security hole, most likely creating a way. to get new confidential information.
“Even if this wiretapping method requires a hanging light bulb and high volume level, it is still extremely interesting. And this is the first time someone has proven this way is possible. Information attacks can only get better, and over time future studies will improve them.“, Boneh experts said.
The team that made the breakthrough was not the first to demonstrate that it could leverage phenomena related to sound waves to eavesdrop. For years, science has known that laser beams hitting glass doors can help outside people hear sounds inside a closed room. In 2014, another team used the gyroscope of a smartphone that could be used as an audio mic.
The technique most similar to lamphone before Ben Nassi and his colleagues discovered this eavesdropping method was “visual microphone – image microphone” discovered by researchers from MIT, Microsoft and Adobe in 2014. By analyzing video captured through a telescope observing an object that is capable of absorbing vibrations placed in a room (for example, a pack of chips or a bonsai pot), the researchers can reconstruct Sound in the room.
However, Mr. Nassi points out that the image-based technique is back, even though it is more convenient to not need a lamp in the room, there is no real-time eavesdropping like lamphone technology. Because the vibrating object is also a light source (light bulb hanging from the ceiling), the photoelectric sensor can capture simpler image data.
The device was used in Nassi’s test.
Nassi thinks this makes lamphone more applicable than previous techniques, when “One can use it in real time and respond to situations in real time“.
Still, Nassi said that his team’s research was not to encourage eavesdropping or imposition of relevant laws, but to show the ability of technology and creativity to reach. He wanted to show people the unexpected holes, so that they know and protect themselves.
The method to combat this advanced eavesdropping method is also simple: closing the window, closing the curtains or turning off the lights are effective. Truly we are living in a society where the eyes and ears are everywhere, even the light that knows how to listen is never redundant.
Refer to Wired