According to the group, a fingerprint of the phone user, photographed from a glass surface, was enough to create a fake finger that could unlock an iPhone 5s secured with TouchID.
Apple had released the new iPhone with a fingerprint sensor that was supposedly much more secure than previous fingerprint technology.
"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 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.
Touch ID, which was only introduced on the top-of-the-line iPhone 5S, lets users unlock their devices or make purchases on iTunes by simply pressing their finger on the home button. It uses a sapphire crystal sensor embedded in the button.
Apple representatives did not respond to requests for comment. If the claim is verified, it will be embarrassing for Apple which is betting on the scanner to set its smartphone apart from new models of Samsung and others running the Android operating system.
Two security experts who sponsored a competition offering cash and other prizes to the first hackers who cracked the iPhone said they had reviewed the information posted on the CCC website, but wanted more documentation.