Apple has added an additional layer of authentication to Face ID on iPhone 18 Pro using image data and a secure exclave, potentially speeding up the process.
Face ID is Apple's most secure biometric authentication system for iPhone and is only matched in terms of security by Optic ID on Apple Vision Pro. The system uses infrared dot projection, attention awareness, depth mapping, and an encrypted mathematical representation of your face to authenticate the user.
With iPhone 18 Pro, Apple has added another layer of complexity to the Face ID system. The tidbit was first discovered by Sam Fathi and shared to social media.
According to updated support documentation, iPhone 18 Pro models supplement captures depth and infrared imagery as usual, but then supplements this with additional image data.
The text specifically says:
On iPhone 18 Pro models or later, this data is supplemented by additional image data to maintain Face ID performance. This information is matched against the stored mathematical representation to authenticate.
The word "maintain" has been called out by social media users as a reference to a potentially weakened Face ID system in the iPhone 18 Pro. Apple moved the dot projector underneath the display, which some assume means worse performance.
However, that seems highly unlikely. Face ID will still perform the same as it always has, even with a partially obscured sensor under a display.
The new system turns off pixels around the sensor to allow the infrared projection to pass through. The only impact this could possibly have is on speed, not on accuracy.
The "maintain" here appears to refer to speed in this case. Users expect a fast authentication system on iPhone, and while having a portion under the display is nice, it is a compromise.
Some users have reported irregular Face ID performance, including slower read times or errors authenticating. There is even a bug with the system that has affected a small number of users and leads to a system crash in iPhone 18 Pro.
AppleInsider staff have a few iPhone 18 Pro models on hand and haven't encountered issues with Face ID or crashes at this time. Your mileage may vary.
The document continues:
Supplemental image data used for Face ID on some devices is processed by the Secure Exclave — a hardware-isolated compartment built into the silicon to process sensor data separately from the rest of the system. Data that is processed and analyzed in the Secure Exclave cannot be accessed by iOS, apps, the user, or Apple.
Apple introduced the secure exclave on M4 and A18 processors. It is a chipset completely separate from the rest of the system that can perform some tasks even if the main chip is compromised in some way.
While the secure enclave is processing depth and infrared data, the secure exclave is processing captured image data into a mathematical representation of the user's face. That data is compared to what is stored in the secure enclave to confirm the user's identity.
While image recognition isn't a reliable form of authentication, combining it with Face ID's biometric data and attention awareness, it is additive to the process. It helps speed the authentication up without decreasing the security protocols in place.
The iPhone 18 Pro released to the public on September 18 with a new under-display component for Face ID. There are some bugs that need to be worked out via an upcoming update, but otherwise it seems iPhone security is more robust than ever.
