How the Accelerometer in Your Phone Could Help Identify You


The tilt sensor in your smartphone, the component that can detect the orientation of your device, can actually produce unique “fingerprints” that could help identify you. Wondering how this is possible? Well, researchers have found that this can happen due to minute hardware variations/imperfections that tend to take place during the manufacturing process of smartphones. The tiny defect causes your phones and tablets to emit data that can allow them to be tracked even when your privacy settings are in place.

Mobile Device Sensors

Research implications

Romit Roy Choudhury, Associate Professor at the University of Illinois, says that the amount of research that go towards tracking the information leakage from mobile devices is in abundance. The accelerometer sensors of almost all smartphone use microelectromechanical systems (or MEMS) to measure the device’s orientation. The MEMS technology accurately calculates the 3D movements of the smartphone that result from a change in electrical capacitance. This, in turn, is due to the action of tiny metal bars that move in coordination with other metal bars present in the accelerometer.

A recent study to determine the accuracy of said unique fingerprints found that the data emitted by the devices varies only slightly with the type of accelerometer used. The study used on 2 tablets and 25 Android devices, and tested on 80 different types of accelerometer chips. It was found that even with different devices, the fingerprints could be determined with an accuracy of 96 percent.

Mobile Security Researcher at Rutgers University, Janne Lindqvist, says that research in the field is still in its beginning stages and since there are no special permissions for using accelerometers, they can be studied stealthily without gaining attention. According to him, although the area of study has huge potential, easy access to smartphones’ accelerometer data should not be provided.

Currently, the raw motions of your smartphone device can be calculated without your permission. Therefore, it is possible to track your phone’s identity even when personal data such as location tracking are turned off. Furthermore, earlier research in the field concluded that even passwords can be inferred from a phone’s accelerometer data based on the taps made on the device.

Future possibilities

Many apps use advertising to expand their customer base, but a number of them are looking for ways to track the users’ web habits for the purpose. Small bits of information, such as your accelerometer and screen orientation details, are used in a variety of mobile games as well as apps such as pedometers. Along these lines, learning your phone habits and integrating it with advertising marketing can be highly beneficial to the growth of these apps.

Additionally, smartphones have several other sensors like magnetometers, mikes, and gyroscopes, which can also send out unique fingerprints of data. According to Choudhury, a combination of all this unique information from different sensors can allow a smartphone or tablet to be tracked anywhere and at anytime. In future, it is possible that the accelerometer data your phone emits can be treated as a personal ID without giving out crucial information.