They've developed a new system that learns how the device's owner interacts with the screen, and then watches how each subsequent interaction is carried out. If the movements don’t match the owner’s profile, the system recognizes the differences and can be programmed to lock the device.
The system is called LatentGesture, and it is going to be presented in Toronto at ACM Chinese CHI 2014 from April 26 to 27. It has been tested in the lab on 20 test subjects, and it has proven nearly 98% accurate on a smartphone and 97% correct on tablets - in the lab.
The test subjects were asked to complete a set of tasks, including tapping buttons, checking boxes and swiping slider bars on a phone and tablet to fill out the form. The system tracked their tendencies and created a profile for each person.
The researchers designated one subject's profile as the owner of each test device and then had the test subjects repeat the earlier test. LatentGesture successfully matched the owner and flagged everyone else as unauthorized users.
"Just like your fingerprint, everyone is unique when they use a touchscreen," said Polo Chau, a Georgia Tech College of Computing assistant professor who led the study. "Some people slide the bar with one quick swipe. Others gradually move it across the screen. Everyone taps the screen with different pressures while checking boxes."
In addition to recognizing the owner, the research team has also configured the system to store 5 profiles, enabling the device to be shared. "This feature could be used when a child uses her dad’s tablet," said College of Computing sophomore Premkumar Saravanan. "The system would recognize her touch signature and allow her to use the device. But if she tried to buy an app, the system could prevent it."
As a passive security system, LatentGesture has a number of advantages over passwords and gestures. At the very least, a thief won't be able to get around your security simply by deducing a security password or gesture simply by looking at the pattern of smudges on the screen.