Things are getting more and more sci-fi all the time, what with artificial intelligence, biometrics and holograms all becoming commercial reality. But University of Washington researchers have pioneered a new wrinkle: on-body transmissions, where the body can take the place of Wi-Fi, Bluetooth or other network.
Talk about "singing the body electric," as Walt Whitman once wrote.
More specifically, the UW engineers devised a way that the data that authenticates identity can travel securely from a phone through the body to a receiver embedded in a device. So a user types a password into a phone while touching, say, a smart door lock or wearable medical device.
Sending a password or secret code over airborne radio waves like Wi-Fi or Bluetooth means anyone can eavesdrop, making those transmissions vulnerable to hackers who can attempt to break the encrypted code. But using benign, low-frequency transmissions within the body eliminates that man-in-the-middle danger.
“Fingerprint sensors have so far been used as an input device. What is cool is that we’ve shown for the first time that fingerprint sensors can be re-purposed to send out information that is confined to the body,” said senior author Shyam Gollakota, UW assistant professor of computer science and engineering.
The technique is described in a paper presented in September at the 2016 Association for Computing Machinery’s International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2016) in Germany.
“Let’s say I want to open a door using an electronic smart lock,” said co-lead author Mehrdad Hessar, a UW electrical engineering doctoral student. “I can touch the doorknob and touch the fingerprint sensor on my phone and transmit my secret credentials through my body to open the door, without leaking that personal information over the air.”
The research team tested the technique on iPhone and other fingerprint sensors, as well as Lenovo laptop trackpads and the Adafruit capacitive touchpad. In tests with 10 different subjects, they were able to generate usable on-body transmissions on people of different heights, weights and body types. The system also worked when subjects were in motion—including while they walked and moved their arms.
“We showed that it works in different postures like standing, sitting and sleeping,” said co-lead author Vikram Iyer, a UW electrical engineering doctoral student. “We can also get a strong signal throughout your body. The receivers can be anywhere—on your leg, chest, hands—and still work.”
Photo © Valery Brozhinsky