Apple explains how the iPhone 18 Pro will prove a photo is real

Apple’s iPhone 18 Pro adds a “Reference Image” mode that signs raw pixels with a sensor-generated key and a Secure Enclave key, then timestamps the capture using Apple’s push-based timestamp service. The signed data uploads to Apple’s Private Cloud Compute, where it is verified, demosaiced, compressed, and signed with a post-quantum RSA-3072 + ML-DSA-87 composite signature. This chain of signatures guarantees indefinite authenticity. The system records sensor confidence scores and can revoke signing for compromised sensors.