Apple 详解 iPhone 18 Pro 如何用密码学证明照片未被 AI 伪造

Serving tech enthusiasts for over 25 years. TechSpot means tech analysis and advice you can trust. First look: Apple added a new camera feature to the iPhone 18 Pro and iPhone 18 Pro Max designed to help establish whether a photograph is authentic. Called Apple Reference Image, the opt-in mode creates a cryptographically protected version of a photo when it is captured. Apple says the system is designed to show that an image was captured by an iPhone camera sensor and has not been altered or generated by AI. When Reference Image is enabled, the camera sensor restarts in a dedicated operating mode. It then signs the pixel data immediately after capture, before the image goes through the usual software-based processing steps. Apple said that's a key difference from other image-authentication methods. Many systems attach provenance data after an image has passed through the software pipeline. Apple argues that this can leave room for tampering before the photo is signed. The company describes the resulting file as a "secure digital negative." It is stored on the phone and contains pixel data, sensor metadata, and cryptographic timestamps. The original reference file is not intended to be edited in the same way as a standard photo. The iPhone's Secure Enclave Processor also signs some capture information from outside the sensor, such as exposure settings, digital zoom, and lens data. Apple said this information is kept separate from the sensor data and cannot change the underlying pixels. A reference image still needs to be rendered into a usable photograph. When a user decides to develop one, the device sends the original negative to Apple's Private Cloud Compute system. // Related Stories Why Gen Z is falling in love with film photography – and rejecting the algorithm along with it Apple just patched a critical macOS flaw that let hackers break in without a password Private Cloud Compute checks the sensor and Secure Enclave signatures, verifies that the device components are associated with the same iPhone, and confirms that the software handling the image has been approved. It then processes the photo and produces a JPEG. Apple said the final image receives a composite signature that combines RSA-3072 with ML-DSA-87, a post-quantum cryptographic algorithm. The company said this approach is intended to keep images verifiable over long periods as cryptographic threats evolve. The system also records a range for the capture time rather than relying on a single timestamp generated by the phone's operating system. The device periodically receives cryptographic time records that provide a lower bound before the photo is taken and an upper bound after capture. Apple said it can add the upper timestamp later if the iPhone is offline when the image is taken. Apple said the system is designed to protect the photographer's identity. Reference Images do not include a public credential that identifies who took the picture, and Apple said the technology is intended to prevent others from publicly linking multiple photos to the same camera sensor. The company also built in a mechanism for revoking images if it detects fraud. Private Cloud Compute assigns each Reference Image a confidence score based on whether it has the expected characteristics of Apple's camera hardware. If Apple finds a security issue, it can invalidate a single image or revoke images associated with an entire sensor. Apple said the revocation process does not require the company to view the photo's content. Apple Reference Image is optional and does not replace the standard camera system on the iPhone 18 Pro lineup. The models also include a 48-megapixel Fusion main camera with a variable aperture, a 48-megapixel ultra wide camera, and a 48-megapixeltelephoto camera that supports 12-megapixel 8x optical zoom. Apple Reference Image is available only through the main camera sensor on the iPhone 18 Pro models. For Apple, the feature aims to provide a technical record of an image's origin at a time when edited and AI-generated photographs are becoming increasingly difficult to distinguish from authentic camera images. Share this article: See more TechSpot in Google Add us as a preferred source and our reporting shows up first when you search. Add TechSpot Featured on TechSpot Records show police justified Flock license plate searches with answers like "LMAO" and "idk" Anthropic CEO warns AI botnet swarms could take over the internet, meanwhile Musk and Altman back slowdown