It’s no secret that fingerprints can be captured and recreated to gain access to mobile devices. Three day after Touch ID appeared on the first iPhone there was a video online showing how it can be beaten.
These videos are often to use to highlight the weakness of fingerprint biometrics on mobile devices. But an instance arose recently where law enforcement asked for help recreating a fingerprint to gain access to a victims mobile, according to a report on Fusion.
Anil Jain, a professor at Michigan State University, was approached by law enforcement to create a 3D replica of a murder victim’s fingerprint. Jain works with a number of different biometric modalities. The victim previously had been arrested and officials had his prints recorded. They wanted access to the mobile device to hopefully find clues as to who committed the crime.
Jain and his PhD student Sunpreet Arora created replicas of all 10 fingerprints. Typically, a 3D printed finger alone can’t unlock a phone. “Most fingerprint readers used on phones are capacitive, which means they rely on the closing of tiny electrical circuits to work. The ridges of your fingers cause some of these circuits to come in contact with each other, generating an image of the fingerprint. Skin is conductive enough to close these circuits, but the normal 3D printing plastic isn’t, so Arora coated the 3D printed fingers in a thin layer of metallic particles so that the fingerprint scanner can read them.”
The process is still being refined and the fingerprint replicas haven’t been turned over to law enforcement yet. Further testing will be done to make sure the replicas works