Apple has added an additional layer of authentication to Face ID on iPhone 18 Pro using supplemental image data and a Secure Enclave, potentially speeding up the process. Face ID remains Apple's most secure biometric system for iPhone, matched only by Optic ID on Apple Vision Pro, utilizing infrared dot projection, attention awareness, depth mapping, and an encrypted mathematical face representation.

Discovered by Sam Fathi and confirmed in updated support documentation, iPhone 18 Pro models now supplement standard depth and infrared captures with additional image data to maintain Face ID performance. This data is matched against the stored mathematical representation for authentication. The word "maintain" sparked speculation about potentially weakened Face ID due to the dot projector moving underneath the display, though Apple turns off pixels around the sensor to allow infrared projection through. The impact appears to be on speed, not accuracy.

Some users report irregular Face ID performance including slower read times or authentication errors, plus a bug causing system crashes on a small number of devices. AppleInsider staff testing iPhone 18 Pro models haven't encountered these issues. Supplemental image data is processed by the Secure Enclave — a hardware-isolated compartment in M4 and A18 processors that prevents access by iOS, apps, users, or Apple.