Apple publishes 'Reference Image' design to sign photos at the sensor on iPhone 18 Pro/Max
Apple published the design for Apple Reference Image, an opt-in camera mode on the main sensor of iPhone 18 Pro and 18 Pro Max that signs pixel data at capture and produces a timestamped DNG 'secure negative' verified via Apple's Private Cloud Compute and signing service rather than post-capture C2PA credentials. The system uses sensor-secure boot, Secure Enclave metadata signing, RFC 3161 timestamps routed via Oblivious HTTP, PCC-verified processing, a composite ML-DSA-87 and RSA-3072 signature, and a neural-network confidence score for revocation, while not publishing the model weights or a cross-platform verifier.