BEWARNED! Smartphone PIN Can Be Hacked Through Camera & Mic

The PIN for a smartphone can be revealed by its camera and microphone using a programme called PIN Skimmer. A team from the University of Cambridge discovered that codes entered on a number-only soft keypad could be identified through this means.

The software watches your face via the camera and listens to clicks through the microphone as you type.

According to the research, the microphone is used to detect "touch-events" as a user enters their PIN. In effect, it can "hear" the clicks that the phone makes as a user presses the virtual number keys.

The camera then estimates the orientation of the phone as the user is doing this and "correlates it to the position of the digit tapped by the user".

How successful is PIN Skimmer? In a test set of 50 4-digit PINs, the app (which has a server-side component for image-processing, so as to avoid suspiciously running down the battery) correctly guessed more than 30 percent of PINs after a couple of attempts, and over half after 5 attempts. Obviously longer PINs help, but even with 8-digit codes, PIN Skimmer still worked out around 45 percent after 5 attempts.