Location and movement can be tracked on Android phones by studying their power consumption, a study has found, without using GPS or Wi-Fi.
Researchers at Stanford University and Israel’s defence research group Rafael have developed a technique called PowerSpy, which can gather data about an Android phone’s geolocation just by monitoring small changes in its battery levels.
Typically, a smartphone uses more power the further away it is from the cell tower or when the connection between the two is obstructed by a building or a hill.
Location is instantly made available to any installed app in use, without user permission, that could pinpoint movements with as much as 90 per cent accuracy.
“The malicious app has neither permission to access the GPS, nor other location providers (e.g. cellular or WiFi network),” said the paper.
“We only assume permission for network connectivity and access to the power data. These are very common permissions for an application and are unlikely to raise suspicion on the part of the victim.”
According to the report, activities such as listening to music, using maps or social media all drain the battery but this could be overlooked due to “machine learning”.
However, tracking movement can only work when placed against a background of pre-existing routes.