An average smartphone these days is packed with a wide array of sensors such as GPS, Camera, microphone, accelerometer, magnetometer, proximity, gyroscope, pedometer, and NFC.
According to a team of UK scientists , hackers can potentially guess PINs and passwords – that you enter either on a bank website, app, your lock screen – to a surprising degree of accuracy by monitoring your phone’s sensors, like the angle and motion of your phone while you are typing. The danger comes due to the way malicious websites and apps access most of a smartphone’s internal sensors without requesting any permission to access them – doesn’t matter even if you are accessing a secure website over HTTPS to enter your password. Smartphone apps usually ask your permissions to grant them access to sensors like GPS, camera, and microphone.
But due to the boom in mobile gaming and health and fitness apps over the last few years, the mobile operating systems do not restrict installed apps from accessing data from the plethora of motion sensors like accelerometer, gyroscope, NFC, motion and proximity.
Researchers were able to guess four-digit PINs on the first try with 74% accuracy and on the fifth try with 100% accuracy based on the data logged from 50 devices by using data collected from just motion and orientation sensors, which do not require any special permission to access.