Security systems that can only be unlocked by fingerprints sound foolproof, but it seems there’s a way around everything, and some experts are concerned that 3D printed hands with stolen fingerprints could be used to get through security at places like banks, immigration counters at airports, and police departments.
The potential threat came to the attention of Michigan State University Distinguished Professor and biometrics expert Anil Jain, who, along with his research team, had been studying the use of 3D printed hands, complete with fingerprints, to test and calibrate fingerprint scanners.
Jain is already familiar with reproducing fingerprints using 3D printing; a few months ago he and PhD student Sunpreet Arora were given the task of 3D printing the finger of a murder victim in hopes of unlocking his smartphone. While no further information has been released about the ongoing investigation, Jain and Arora seemed to be getting close, using metallic ink to coat the 3D printed fingerprint to react with the phone’s screen. In a study entitled “3D Whole Hand Targets: Evaluating Slap and Contactless Fingerprint Readers,” Jain, Arora, and Nicholas G. Paulter, Jr. of the National Institute of Standards and Technology (NIST), describe how they created a 3D printed hand that can be worn like a glove and used to access two types of fingerprint scanners: slap readers, which require the whole hand to be placed directly on the scanner, and contactless readers, which only require that the hand be waved in front of the scanner.
“Like any optical device, fingerprint and hand scanners need to be calibrated, but currently there is no standard method for calibrating them,” said Jain. “This is the first time a whole hand 3-D target has been created to calibrate fingerprint scanners. As a byproduct of this research we realized a fake 3-D hand, essentially a spoof, with someone’s fingerprints, could potentially allow a crook to steal the person’s identity to break into a vault, contaminate a crime scene or enter the country illegally.”
Using a high resolution Stratasys Objet350 Connex3 3D printer, the team 3D printed hand models from rubberlike materials that simulate the texture and feel of a real human hand, with fingerprints that had been extracted from impressions taken by a slap scanner. The research demonstrated that 3D printing was capable of reproducing clear, accurate impressions of real fingerprints on a fake hand, which is good news in terms of more effective scanner calibration methods, but could be bad news for security. While the researchers’ study was to demonstrate the efficacy of 3D printed hands for scanner testing purposes, Jain says it’s now the responsibility of scanner manufacturers to prevent possible criminal use of the technology.
“We have highlighted a security loophole and the limitations of existing fingerprint scanning technology, now it’s up to the scanner manufacturers to design a scanner that is spoof-resistant,” he said. “The burden is on them to tell whether the finger being placed on the scanner is real human skin or a printed material.”
Jain and his team are continuing to experiment with 3D printed hands, including using conductive silver and gold inks to unlock capacitive scanners like those used for mobile phones. The study was sponsored by NIST in hopes of developing consistent standards for the reliable testing of fingerprint standards, but Paulter, Group Leader for the Security Technologies Group at NIST, thinks that the FBI, CIA, military and other agencies and manufacturers will be very interested in the study as well. The paper received the Best Paper award at the 2016 International Conference of the Biometrics Special Interest Group. Discuss in the 3D Printed Fingerprints forum at 3DPB.com.[Source/Images: Michigan State University]