Did you know? Your smartphone battery can reveal your location, track you
All smartphones today integrate sensors and radios, which communicate with the external servers. These could be GPS, Wi-Fi or mobile data, which indirectly give out your location via the service provider. However, you could turn off your GPS, Wireless and your mobile data to ensure that your position is not shared with any of the services that you are using. But then, you will not be able to use important services that are clubbed with apps, such as maps, social networking apps and alike, which use the location-based services to determine your global position.
Operating systems such as iOS and Android have the feature to prevent third-party apps from accessing your location data without your permission. However, did you know that your mobile phone can be tracked by simply analysing the way it consumes power? Yes, it can.
A study done by Yan Michalevsky at Stanford University in California and a few pals revealed the shocking reality that malicious software can determine the global position of your smartphone by simply analysing the way the device uses power. The device can be tracked in real-time.
Well, it is not a new finding, but smartphones consume battery, according to the signal strength. The power usage of a smartphone depends on the distance of the device from the nearest telecom base station. When you move around, the distance of your smartphone from the base station also increases or decreases. This puts a load on the smartphone’s transceivers and power is either increased or decreased, depending on the distance of communication.
In this way, when the power consumption from the battery is fluctuating, it can be correlated with movement and direction. However, if you are not moving, the power consumption remains steady, and you cannot be tracked. Hence, in order to track your position, you must be moving, continuously.
On the other hand, the tracking software should be aware of the base stations on the route, the amount of power the base is transmitting/receiving and the number of diversions on the route. It isn’t as simple as one would think, but not impossible.
To find out how well this technique works in practice, Michalevsky and Co created an Android app called PowerSpy that measures power usage. They then tested it on a number of Nexus 4 devices. In total, they took 43 different power usage profiles on four different routes each about 14 kilometres long. They then analysed the power usage profiles to see if they could determine which route had been taken for each. It turned out they could do this with accuracy of 93 per cent. In these experiments, the data was analysed from the phone’s power ampere meter, which measures the amount of power the battery is draining and at what speed.
So how can this method of tracking be stopped? One is by preventing apps from accessing the power usage of the device. So the next time you download a new app, make sure you read up on what the app is accessing, and why would it need to. You may end up with spy software with a completely genuine application.
