The more intertwined technology becomes in our daily lives, the more important it is to safeguard all that information we keep on our devices. One way smartphone manufacturers have developed to do that is fingerprint scanning, as no two prints are identical. But a new study suggests that system might not be as secure as you think.

In a new study published in the journal IEEE Transactions on Information Forensics & Security researchers from New York University and Michigan State University claim to have created “master fingerprints” that can be used to trick smartphone fingerprint scanners in about 65% of cases.

These fake prints were made by using patterns found in real finger prints, and were tested in computer simulations instead of on real smartphones.

Still, the researchers warn that the technology used to fake the prints is improving quickly, calling into question the security of such scanners.

Part of the problem is that smartphone fingerprint scanners are generally smaller than your typical adult fingertip. That’s why, when setting up this biometric lock on a device, users generally have to place different parts of their finger on the scanner to be recorded. It’s putting all those smaller snapshots together so that you can later unlock your phone without having to worry about which part of your fingertip hits the scanner.

“There’s a much greater chance of falsely matching a partial print than a full one, and most devices rely only on partials for identification,” one of the study’s authors, Nasir Memon, tells The Telegraph.

Phones usually let you try a few times before shutting down the fingerprint scanner, Memon notes, so you could ostensibly make a glove with five different fingerprints that would grant you access to half of all iPhones before your five tries are exhausted.

Just like any other security measure, biometrics are not hack-proof. Last month, it was reported that the new facial recognition lock on the Samsung Galaxy S8 could be fooled by a photo.

The technology needed to make master fingerprints that can fool any phone is still in early stages, so you probably don’t have to worry just yet. Just keep a close eye on your phone — after all, if they can’t get their hands on it in the first place, they’ll have a hard time fooling the fingerprint scanner.

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