Apple’s Touch ID Is A 500ppi Fingerprint Sensor Built Into The iPhone 5S Home Button

Remember those persistent rumors of a fingerprint sensor that would be baked into the iPhone 5S? Well, it’s not a rumor any longer — Apple has just confirmed that the iPhone 5S will feature a 500ppi fingerprint sensor right in the 5S’ home button.

It seemed like a puzzling addition at first, but the company just shed some light on what the sensor actually brings to the table. Users will be able to simply touch their home buttons (rather than swipe the screen) to unlock their iDevice, but more importantly, Touch ID can be used to authenticate your iTunes purchases. Granted, the prospect of giving your fingerprint to Apple seems like a conspiracy theorist’s dream come true (though the events of the past few months make such concerns much more understandable), but Apple says that user fingerprints will be encrypted and will not be available to third parties.

Apple is hardly the first to bring a fingerprint sensor to a smartphone — Motorola Mobility baked one such sensor into the back of its 2011 flagship the Motorola Atrix, which allowed users to swipe their fingers across it to unlock the device. The crucial issue though was that the sensor itself seemed awfully finicky and wouldn’t always correctly accept a user’s finger inputs. That little stumbling block ultimately meant that the fingerprint sensor wound up being more hassle than it was worth in most cases, and I’m sure that’s a problem that Apple had to tackle head-on when developing Touch ID.

So how exactly has Touch ID been implemented? The home button is now made of sapphire glass to reduce the potential for damaging one of the 5S’ most notable features, and it’s bounded by a steel “detection ring” that determines when your finger is on the home button and fires up the Touch ID sensor. Touch ID is also capable of keeping tabs of multiple different fingerprints, so you (hopefully) won’t have to worry about your friends buying embarrassing songs with your iTunes account with a single touch.

This is a developing story, please refresh for updates.