"In reality, Apple's sensor has just a higher resolution compared to the sensors so far. So we only needed to ramp up the resolution of our fake", said the hacker with the nickname Starbug, who performed the critical experiments that led to the successful circumvention of the fingerprint locking. "As we have said now for more than years, fingerprints should not be used to secure anything. You leave them everywhere, and it is far too easy
to make fake fingers out of lifted prints."
The iPhone TouchID defeat has been documented in a short video:
The method follows the steps outlined in this how-to
with materials that can be found in almost every household: First, the fingerprint of the enroled user is photographed with 2400 dpi resolution. The resulting image is then cleaned up, inverted and laser printed with 1200 dpi onto transparent sheet with a thick toner setting. Finally, pink latex milk or white woodglue is smeared into the pattern created by the toner onto the transparent sheet. After it cures, the thin latex sheet is lifted from the sheet, breathed on to make it a tiny bit moist and then placed onto the sensor to unlock the phone. This process has been used with minor refinements and variations against the vast majority of fingerprint sensors on the market.
"We hope that this finally puts to rest the illusions people have about fingerprint biometrics. It is plain stupid to use something that you can´t change and that you leave everywhere every day as a security token", said Frank Rieger, spokesperson of the CCC. "The public should no longer be fooled by the biometrics industry with false security claims. Biometrics is fundamentally a technology designed for oppression and control, not for securing everyday device access." Fingerprint biometrics in passports has been introduced in many countries despite the fact that by this global roll-out no security gain can be shown.
iPhone users should avoid protecting sensitive data with their precious biometric fingerprint not only because it can be easily faked, as demonstrated by the CCC team. Also, you can easily be forced to unlock your phone against your will when being arrested. Forcing you to give up your (hopefully long) passcode is much harder under most jurisdictions than just casually swiping your phone over your handcuffed hands.