As early as the release of iPhone X, there were still many concerns about the unlocking of Face ID on iPhone X. Later, Craig Federighi, Apple's software engineering director, also answered some hot questions about iPhone X's Face ID technology. However, we still have concerns about some details of Face ID. For example, what is the privacy performance of Face ID? Can I unlock my phone like the rumored photo?

A few days ago, Apple shared a very detailed security white paper on Face ID. This white paper describes in detail how the Face ID of iPhone X works, under what circumstances will Face ID be enabled and used, and how to set Face ID, including some behaviors that may lead to the disabling of Face ID.

1. Operating principle

Face ID uses the latest depth camera of iPhone X to capture the user's facial data and create a facial data map; At the same time, the iPhone X captures the infrared image of the face through the front infrared lens. Start the independent neural engine of the A11 bionic chip, process the user's face data just captured, and compare it with the face data registered by the previous user.

In addition, Face ID can automatically adapt to user's appearance changes, such as makeup or beard. If the appearance of the user is too different, Face ID will first let the user use a password to verify their identity, and then update the user's new face data synchronously. Even when wearing hats, scarves and even various sunglasses, Face ID still works normally.

2. Privacy

Face ID data will be encrypted and protected in the security area specially designated for iPhone X, and these data will be updated and optimized every time the user successfully unlocks with Face ID.

In addition, The data stored by Face ID will never leave the iPhone X, nor will it be automatically backed up to iCloud or other locations.

3. Security

According to the white paper, the probability of iPhone X's Face ID being unlocked by others is only 1/1000000, while the probability of previous Touch ID fingerprint identification being unlocked by others is 1/50000! Security is 20 times higher than before! In addition, face ID unlocking is only allowed to fail five times. After five failed attempts, you can only enter the password to unlock.

Apple has adopted a complex anti fraud neural network in the design of Face ID, and ordinary photos, masks and other camouflage technologies cannot be authenticated.

In addition, Face ID also adds motion awareness, It can identify whether the user's glasses are open, so that others cannot unlock your iPhone X when you are asleep.

4. Applicable scenarios

In most cases, the most suitable distance for using Face ID is 20-50cm.

It is worth noting that the depth camera of iPhone X will be activated intelligently, for example, when you lift iPhone X, new information will wake up the screen.

Even when you are browsing the web, the original camera will judge whether you are looking at the screen. If you have not looked at the screen for a certain period of time, iPhone X will automatically turn off the screen.

5. Protective measures

Password must be set before using Face ID. In the following cases, you must enter a password to complete additional security verification:

Equipment startup or restart;

The equipment has been locked for more than 48 hours;

The iPhone X password has not been used to unlock the device in the past 6 days, and the face ID has not been used to unlock the device in 4 hours;

The equipment has received the command of remote locking;

Face ID unlocking failed five times;

Press and hold the volume key and wake-up key for 2 seconds at the same time, after the shutdown/SOS emergency contact is initiated;