Here's how the iPhone 18 Pro's Apple Reference Image tech works

Apple’s iPhone 18 Pro and Pro Max feature a Reference Image mode that signs each photo with a cryptographic key embedded in the camera sensor. The sensor’s key, certified at manufacturing, and a separate security-processor key sign the capture record. Apple’s Private Cloud Compute verifies the signature and attaches a digital signature to the final image. The mode stores a DNG raw file linked to the photo, includes a cloud-signed timestamp window, and retains the raw data in the Photos app until deletion after 30 days.