Many of us rely on using our fingerprints to unlock our phones and pay for shopping. But smartphone fingerprint scanners may not be secure as we think.
Researchers have developed a series of 'MasterPrints' made from the common features of human finger markings which they say can unlock any smartphone.
MasterPrints are artificial mosaics made from the common elements of all human finger markings. The surface of our fingers are covered in swirling friction ridges, which have evolved to heighten our sensitivity to touch.
The intricate pattern these ridges form on our fingers are unique to every person and no two fingerprints are the same.
But there are three basic fingerprint patterns that all ridges follow, which are known as the loop, whorl, and arch patterns.
While 60 to 65 per cent of all people have a loop pattern on their fingerprints, 30 to 35 per cent have a whorl and around five per cent have an arch.
The researchers made use of these common patterns to create MasterPrints that roughly match a large number of real finger markings.
Scientists from New York University and Michigan State University found the artificial prints can unlock any phone 65 per cent of the time.
The digital fingerprints work by exploiting the way smartphone scanners analyse a finger. Smartphone scanners are so small that they have to take multiple pictures of your finger or thumb, leaving more room for error.
'A number of consumer electronic devices, such as smartphones, are beginning to incorporate fingerprint sensors for user authentication,' the scientists said in a research paper.
'The sensors embedded in these devices are generally small and the resulting images are, therefore, limited in size.
'To compensate for the limited size, these devices often acquire multiple partial impressions of a single finger during enrolment to ensure that at least one of them will successfully match with the image obtained from the user during authentication.'
Smartphones also let users to save several finger and thumb prints. Because a print only has to match one saved image to unlock the device, the sensor is more vulnerable to error.
'It's as if you have 30 passwords and the attacker only has to match one,' Professor Nasir Memon, from New York University, told the New York Times.
Fingerprint scanners are incorporated into the home button of the iPhone 5 and newer Apple models, and on the front or back of most new Android devices.
But Apple said the chance of error for their fingerprint sensors is just one in 50,000 if one finger is saved, according to the New York Times.
A company spokesperson added Apple had various other security features to prevent hackers getting into a stranger's phone.
For example, Apple requires you to enter your PIN rather than your fingerprint when you first switch on your device.