Now this really proves all those features about smartphone fingerprint sensors being proved unsafe. Please welcome, the Master Print. People are starting to love the new trend of fingerprint scanners built into smartphones as a security measure to unlock your device. One advantage to fingerprint scanners is that it makes it faster to unlock handsets than typing a pin number. It’s also supposed to be more secure because (you probably keep seeing this in the CSI TV series) all of us have unique fingerprints. As a result, a fingerprint scanner stops someone else unlocking your phone because the sensor will only read the owner’s fingerprint.
But it turns out that computer scientists at the New York University and Michigan State University have been working on developing digital “master prints.” These are the biometric equivalent of master keys that are capable of tricking a variety of fingerprint sensors that are trained to recognize your “unique” fingerprints. According to Nasir Memon, a computer scientist at NYU’s Tandon School of Engineering who co-authored the study, “Our work shows that there are these things called ‘masterprints,’ which could be used. If they had a master print that maximized their probability of success, they may be able to get through a device’s fingerprint system.”
As Memon further explained, the problem is that fingerprint sensors tend to be small. Because of this, they match according to partial fingerprints, rather than whole ones. When you register your fingerprint on a new device, it breaks down your single print into a number of smaller squares. This means that, regardless of how your finger is placed on the fingerprint sensor, your mobile device is able to recognize it. When a full fingerprint is taken there is some amount of uniqueness in it, even if it’s not total. The problem is that, as you start taking partial fingerprints, the distinguishability drops considerably. As an analogy, if you think about a face, they’re distinct because two people are unlikely to have the same face. But if you just take a part of the face, the chances of two people having that partial face become are higher.
Video Courtesy of Youtube:
The research team from the two prestigious universities analyzed a database of 800 fingerprints, from which they extracted thousands of partial prints. According to their analysis, a master print is able to emulate a variety of partial fingerprints that could be used to fool a random fingerprint scanner 26 to 65 percent of the time. The researchers though, are taking note that this work is still hypothetical. They did not create physical master prints but rather carried out their work using computer simulations. The idea of a master print glove, with a different master print on each finger, fortunately, does not exist yet, but it is still a reminder of some of the perils that exist with biometrics, especially for phone sensors.