Android phones can be tracked without using their GPS or wi-fi data by studying their power use over time, a study has found. A smartphone uses more power the further away it is from a cellular base and the more obstacles are in its way as it reaches for a signal.

Additional power use by other activities could be factored out with algorithms, the researchers found. They created an app designed to collect data about power consumption.

"With mobile devices now becoming ubiquitous, it is troubling that we are seeing so many ways in which they can be used to track us," said cyber-security expert Prof Alan Woodward, from Surrey University.

dailytechinfo.org