Apple has introduced a Reference Image mode on the iPhone 18 Pro and Pro Max, designed to prove that a photo is genuine and hasn't been altered by AI or editing tools. As deepfakes and AI-generated images become harder to spot, the feature aims to give photos a verifiable "tamper-proof seal," using cryptographic signatures rather than visual clues like distorted hands or text to establish authenticity.

The system works by embedding a unique cryptographic key inside the camera sensor itself at manufacturing, which signs image data the moment it's captured, before Apple's Private Cloud Compute service verifies the record and adds a further digital signature. It also links the sensor to the phone's security processor to stop swapped sensors being used to fake images, stores evidence in RAW DNG format for up to 30 days after editing, and records a signed timestamp window independent of the phone's own clock, even working offline. The feature is opt-in and must be switched on via Settings > Camera > Reference Image.