Wednesday, August 9, 2017

iPhone 8: How Face ID could work

Thanks to the accidentally leaked HomePod firmware, 1 it’s almost certain that Touch ID will not continue in the iPhone 8. Apple may be opting for a face unlocking feature dubbed ‘Pearl ID’.

Facial biometrics have always been a lacking mechanism for security, at least in the consumer market. It’s pretty bad in most implementations, so everyone is up in arms about this feature possibly replacing the tried-and-true Touch ID we’ve had since the iPhone 5S. Which, if you remember, doubters largely acted the same way about fingerprint sensors when Touch ID was announced. The point is: everyone seems to forget that Apple undoubtedly has found ways to overcome the downsides of these implementations, or they wouldn’t be doing this.

Since Pearl ID is a speculated name, let’s just call it Face ID for the sake of this post. Here’s how I could see it working.

Unlocking the Phone

Apple changed the unlocking behavior in iOS 10 from a press of the home button to simply resting your finger on it. I now believe Apple made this change to pave the way for Face ID. Why? Let’s think about what’s required to only unlock an iPhone right now with Touch ID.

Unlocking with Touch ID

  1. Wake your phone via:
    • Raise to wake.
    • Pressing the Sleep/Wake button.
    • Pressing the Home button with a non-registered finger.
  2. Rest your finger on the Touch ID sensor.

You can then take action on your notifications, press the Home button to go Home, launch straight into apps from the widget screen, etc. You’re authenticated.

Unlocking with Face ID

  1. Wake your phone via:

Where’s step two, you say? That’s the beauty of it — step two is handled by the phone. Whenever you are looking at the phone while the Lock Screen is presented, Face ID would authenticate you. You can then perform all the normal actions from the Lock Screen like usual. If you look away, the phone is instantly locked again.


  • No need to specifically unlock your phone.
  • Faster access for acting on notifications.
  • Potentially more secure than Touch ID.
  • Low false positives, given that the iPhone will purportedly use 3D-sensing cameras to differentiate between a picture of your face and your actual face.

Making Purchases: App Store & Apple Pay

Touch ID can also be used to make purchases in the App Store and iTunes Store, as well as authenticate payments for Apple Pay. Here’s how Apple could replicate this with Face ID and a gesture.


  • Instead of a Touch ID prompt, you are presented with a Face ID prompt and an on-screen button.
  • Simply look at the phone and hold an on-screen button for 3 seconds.

Face ID provides the biometric authentication, while holding an on-screen button would indicate intent. It also would give you time to back out (something that is actually a little harder to do with Touch ID). This would work for both App Store Purchases and Apple Pay. With Apple Pay, you would hover your iPhone over the NFC terminal like usual, then follow the process outlined above. Same goes for sending Apple Pay Cash to friends and family when iOS 11 launches in the fall.

iPhone 8-Specific Feature: App Locking

With this kind of ambient authentication, I think the iPhone 8 has the potential to receive special features taking advantage of Face ID. One I can think of is App Locking, something frequently requested to this day for use with Touch ID.

In other words, apps are only allowed to show their content if you are actively looking at the phone. Take a banking app for example. You would launch it, but it wouldn’t show anything until you actually look at the phone and are authenticated by Face ID. To take it one step further in theory: once you look away, the content could be hidden until you look back again.

The Sleep/Wake Button

I think the Face ID change is what could be driving a larger Sleep/Wake button to be present in the leaks that have come out. Because of Face ID’s ambient nature, we may benefit from easier access to the Sleep/Wake button. Making it longer would help enable that.

Also, it makes sense to differentiate this button in size from the volume up/down buttons. I never could understand why Apple made them the same size in the first place, other than for congruency. Quite a few times while trying to lock the phone while holding it a specific way, I’ve pressed both the Sleep/Wake button and Volume Down button. I’ve read others have experienced the same thing, so it would be nice to not accidentally do this anymore.

The Cover Sheet

iOS 11 replaces Notification Center with the Cover Sheet, which blurs the lines between the Lock Screen and the old Notification Center. A puzzling change to this date, Federico Viticci speculated this morning on Twitter that it may provide a way to lock the iPhone 8. While I initially disagreed with this theory, I think it’s plausible if you take into account the ambient nature of Face ID as outlined above. I would perhaps just question calling this the Cover Sheet on iPhone 8, instead of just Lock Screen.


Thinking this through has made me excited for Face ID and highlights the flaws of Touch ID. This kind of interaction would be something Apple is great at: simplifying things we already thought were perfect. We’re looking at our phones all the time anyway — might as well make use of our beautiful mugs.

  1. A gift that keeps on giving.