Claim signature
Definition
An X.509-based digital signature over the hashes of all assertions in a claim plus the content binding hash. Produced by the signer's private key and verified against the signer's certificate, which must chain to a root in the C2PA trust list.
Related terms
- Assertion
- A single provenance statement inside a C2PA claim. Examples include the camera make and model, GPS coordinates at capture, an AI-training or...
- C2PA manifest
- The structured provenance record embedded in or associated with a media file. Contains one or more signed claim blocks, each holding a...
- C2PA trust list
- A curated list of trusted root certificate authorities whose chains can anchor a C2PA claim signature. Maintained by the C2PA organisation. A...
- Hard binding
- A content binding that stores SHA hashes of specific byte ranges of the media file inside the signed manifest. Any modification to...
- Soft binding
- A content binding using a perceptual fingerprint or watermark embedded in the signal rather than the file bytes. Designed to survive format...
Explained in
- C2PA and Content Credentials: Cryptographic Provenance StandardsAn X.509-based digital signature over the hashes of all assertions in a claim plus the content binding hash. Produced by the signer's private key and verified...