Your phone could soon warn you if someone is taking a sneaky peek at the screen over your shoulder.
A new feature, dubbed the electronic screen protector, is being designed by two Google researchers to ensure people can view private content like bank details in public places without the risk of it being seen.
An example video, posted by researchers Hee Jung Ryu and Florian Schroff, demonstrates how the phone knows when a stranger is looking at the screen using the front-facing camera.
It immediately puts the camera’s view on screen, pointing out where the person is by highlighting their face and showing the words “stranger looking alert”.
The developers say this allows users “to continue reading private and confidential contents on (their) mobile device, while protecting their privacy from onlookers in a crowded space such as the subway or an elevator”.
The feature demonstrates a different use for the sort of face detection technology currently being used by Apple in its iPhone X for logging in and powering animoji.
According to the researchers, the system works in varying light conditions and with the peeker’s head in different positions.
It takes just two milliseconds to detect someone’s gaze, they say, and 47ms to recognise a face – quick enough to ensure anyone trying to see your screen shouldn’t be able to glean anything useful.
There is no suggestion at this stage that Google is looking to put the feature into commercially available phones, but the researchers will present their work at the Neural Information Processing System conference in California next week.