Using music to covertly track body movements

SEATTLE: As smartphones, tablets, smart TVs and other smart devices become more prevalent in our lives, computer scientists have raised concerns that these networkenabled devices, if not properly secured, could be co-opted to steal data or invade user privacy.

Now researchers at the University of Washington have demonstrated how it is possible to transform a smart device into a surveillance tool that can collect information about the body position and movements of the user, as well as other people in the device’s immediate vicinity. It works even through walls.

Their approach involves remotely hijacking smart devices to play music embedded with repeating pulses that track a person’s position, body movements, and activities both in the vicinity of the device as well as through walls.

They showed how it is possible to collect such detailed data on personal activity using Covert Band, software code they created to turn smart devices into active sonar systems. CovertBand can use built-in microphones and speakers in a smart device — and can be controlled remotely.

“To our knowledge, this is the first time anyone has demonstrated that it is possible to convert smart commodity devices — like smartphones and smart TVs — into active sonar systems using music,” said senior author Shyam Gollakota, a UW associate professor of computer science and engineering.

“And the physical information CovertBand can gather — even through walls — is sufficiently detailed for an attacker to know what the user is doing, as well as other people nearby.”

Said co-lead author Rajalakshmi Nandakumar, a UW doctoral student: “Most of today’s smart devices including smart TVs, Google Home, Amazon Echo and smartphones come with built-in microphones and speaker systems — which lets us use them to play music, record video and audio tracks, have phone conversations or participate in videoconferencing.

“But that also means that these devices have the basic components in place to make them vulnerable to attack in this manner.” — UW News

— Photo by Dennis Wise/University of Washington Doctoral student Rajalakshmi Nandakumar demonstrates the simple walking motion that CovertBand can detect.