Research conducted at the University of Illinois has shown the existence of trackable fingerprints in smartphone sensors.
Associate Professor Romit Roy Choudhury and graduate students Sanorita Dey and Nirupam Roy showed that the fingerprints exist largely because of imperfections during the manufacturing hardware process, according to Product Design & Development.
The study was published at the Network and Distributed System Security Symposium (NDSS), a huge conference on wireless and web security held in San Diego last February. The findings also won the "Best Poster" award at the HotMobile international workshop in 2013.
Researchers found that each phone's sensor had its own "fingerprint". Third parties could keep track of what the device's user was doing at what time by identifying the fingerprint in sensor data sent from the phone, Gizmag reported.
The university described smartphone sensors as similar to sugar cookies made with the same dinosaur-shaped cookie cutter. While all of the cookies might look like the same animal at first glance, each one has its own differences. For sensors, these differences leave a unique fingerprint in the data. Casual users may not be able to find the fingerprint, but people who are looking deeply might be able to locate it.
The researchers focused specifically on the accelerometer, but also found that other sensors could leave certain fingerprints, Product Design & Development reported. They tested 80 standalone accelerometer chips, 25 Android phones and 2 tablets over the course of nine months.
To make sure the fingerprints were not defects resulting from a specific production line, the accelerometers were chosen from different manufacturers. The researchers were able to identify the different sensors with 96 percent accuracy.
"We do not need to know any other information about the phone- no phone number or SIM card number," Dey said. "Just by looking at the data, we can tell you which device it's coming from. It's almost like another identifier."
The researchers said it is possible to track a user with fingerprints from cameras, microphones and gyroscopes as well, Gizmag reported. Combining these fingerprints would provide even greater accuracy.
While no solution to this dilemma has been put forth, researchers suggested that users should not share sensor data with an app before thinking about how strong its security is.
