Severed fingers can't unlock iPhone 5s

It is not possible for a severed finger to unlock an iPhone 5s.

Apple’s latest flagship smartphone uses fingerprint technology to replace other login methods. That raised concerns over an escalation in violent muggings, in which criminals may cut off victims’ fingers to access a stolen iPhone. However, experts in biometric security have said that it is not possible to unlock an iPhone 5s using a severed finger. At the unveiling of Apple’s new iPhones last week, it revealed that the 5s’ Touch ID fingerprint sensor uses radio frequency scanning to read the sub-epidermal lays of your skin. According to experts, that technique requires your finger to be alive, and as such, attached to the iPhone owner. “The [RF capacitive sensor] technology is built in a way that the [fingerprint] image has to be taken from a live finger,” Sebastien Taveau, chief technology officer at Validity Sensors told Mashable. “No one in biometrics wants to talk about cut fingers and dead bodies, but at the end of the day we are still asked to remove the fears of consumer and make sure that they understand that [a severed finger] will not work.” It is still possible however, for a criminal to force the victim to unlock their iPhone and authorise their own fingerprint on the device. However, it is believed the length of time it would take to do this makes it undesirable. Taveau also hit out at claims that Apple is no longer innovating. He pointed to the fingerprint scanner and said it is a classic example of Apple taking an existing technology and making it mainstream. “[Apple] used a technology that’s been around for a long time, but the big difference is that they made it cool,” says Taveau. "It’s been around on laptops, but besides locking and unlocking your laptop there was not much of a use case for it. “Now with Apple, by actually building an experience, they are educating the market, which is very important… Expect to see the Android world shipping [these kinds of] devices in the next couple of months.”