Forget cookies, how you swipe on your phone is enough to track you
A research paper titled "Touch and You're Trapp(ck)ed: Quantifying the Uniqueness of Touch Gestures for Tracking" goes into great detail analyzing something the scientists call "touch-based tracking". The team used a specially designed app and 89 participants to test out their theoretical models.
While the app was designed to gather the needed amount of different gestures faster, by letting the users play various games, the raw data came from the Android API MotionEvent (iOS has similar APIs available as well), which can be accessed by developers without any security permissions.
The main type of gestures they were interested in were swipes, something you might think isn't really that distinct, but also gathered taps, keystrokes and handwriting.
Once the scientists had enough gesture samples, they analyzed the data and came to some interesting conclusions. Left swipes alone can provide 68.6% of the information needed to identify the user. Combining all the tracked gestures provided 98.5% of the information.
Here is where touch-based tracking gets to the next level: because the way you interact with your phone is connected to your physical self and not some account, using this tracking method allows to distinguish between people using the same account, as well as track users between different devices.
Imagine seeing an ad for the new 6-bladed razor on your phone, then looking up something on your wife's tablet and seeing the same ad. While that might be an advertiser's dream come true, the researchers rightfully point out that it is also raises serious privacy and security concerns. They did, however, come up with at least one useful application: automatic parental control enabling when your kid touches a device.
We're not sure how long it will be before developers start integrating touch-based tracking, but we're practicing our new swipes just in case.
source: Sciendo via Cnet