A research team from the University of Singapore has demonstrated how the lidar system of a robot vacuum cleaner can be hacked to record private conversations.
The method, called LidarPhone, repurposes the navigating sensor of a vacuum robot into a laser-based microphone.
According to the researchers, by reflecting lasers off common objects located near a computer speaker or television soundbar, a hacker could obtain information about the original sound that made the object’s surfaces vibrate.
The attacker would then use applied signal processing and deep-learning algorithms to recover speech from the audio data and potentially obtain sensitive information, such as a person’s credit card or bank account numbers.
In experiments, the team, led by computer science assistant professor Jun Han, and doctoral student Sriram Sami, used a common robot vacuum cleaner with two sources of sound. One was the voice of a person reading out numbers played from a computer speaker, while the other source was music clips from television shows played through a television soundbar.
According to the team, the system was able to detect the digits being spoken aloud with high accuracy.
Regarding the second sound source, the team collected some 19 hours of recorded audio files and passed them through deep-learning algorithms that were trained to either match human voices or identify musical sequences.
Sami said: “The proliferation of smart devices, including smart speakers and smart security cameras, has increased the avenues for hackers to snoop on our private moments.
“Our method shows it is now possible to gather sensitive data just by using something as innocuous as a household robot vacuum cleaner. Our work demonstrates the urgent need to find practical solutions to prevent such malicious attacks.”
To prevent such attacks, the research team suggested disconnecting vacuum robots from the internet and recommended that lidar manufacturers incorporate a mechanism that cannot be overridden, to prevent the internal laser from firing when the lidar is not rotating.