Sam Shead/BI

An Android lock screen pattern is entered.

If you use a lock screen pattern to protect your Android phone, it is far less secure than you might think.

That’s the message from researchers at the University of Lancaster, who explained in a paper how they were able to reconstruct people’s lock screen patterns with high accuracy using discreetly captured footage. (See the full study below.)

Lancaster University

Examples of how the computer algorithm was able to recognize the pattern.

If you’re not familiar with lock screen patterns – perhaps because you’re using iOS – they’re an alternative way to secure your smartphone on Android. Instead of entering a passcode or using your fingerprint, you draw a pattern of your choosing in one continuous motion.

To do this, however, you have to move your fingers – and with the right software, these movements can be reverse-engineered.

The researchers not For the method to work, people need to be able to see the screen, they write. Instead, covert recordings are made from a smartphone from about two meters away or from a professional SLR camera up to nine meters away – was enough to automatically reverse engineer the pattern using a computer vision algorithm.

The algorithm identifies one or more possible patterns from the footage and, in a study of 120 unique patterns, was able to figure out over 95% of them in five attempts or less – before the device automatically locked due to too many incorrect pattern entries.

“The size of the screen or the position of the pattern grid on the screen does not affect the accuracy of our attack,” the researchers wrote. And furthermore: “Complex patterns do not actually provide stronger protection in our attack than simple patterns.”

The result is that pattern locks are not a particularly secure way to store your data and secure your device, the researchers say. It’s relatively easy for anyone to secretly record you unlocking your device in a public place.

If your device is encrypted and someone steals it, your data is usually safe, but if the person can figure out your lock screen pattern beforehand, the situation suddenly becomes more serious.

Here is the full study:

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The post “Researchers found it’s shockingly easy to crack Android users’ lock screen patterns” first appeared on Business Insider.