Content Authenticity Initiative (CAI)

Unlike simple metadata tags that can be stripped, the CAI framework records a complete ingredient chain that documents every transformation applied to an asset. Each edit generates a new manifest that links back to the previous version.

• Immutable Log: Each action (crop, filter, composite) is recorded as a cryptographically hashed entry, creating a Merkle tree of provenance.
• Derivative Tracking: If a video clip is extracted from a longer recording, the clip's manifest contains a hard reference to the original master asset.
• Gap Detection: Any break in the chain of custody is immediately visible to a validator, flagging potential unauthorized manipulation.

The CAI framework is not a monolithic standard but a composable architecture defined by the C2PA specification. It separates the concerns of data storage, signing, and validation into distinct layers.

• JUMBF Box Format: Provenance data is stored in a standard JPEG Universal Metadata Box Format container, ensuring backward compatibility with legacy file formats.
• Pluggable Signing Algorithms: The framework supports various cryptographic suites, allowing organizations to comply with specific regulatory requirements (e.g., FIPS 140-2).
• Validation Engine: A standardized verification algorithm parses the manifest, checks the signature chain, and outputs a pass/fail status along with a detailed trust report.

A tamper-evident, cryptographically signed set of metadata that functions as a digital nutrition label for content. Content Credentials are the user-facing manifestation of CAI provenance data.

• Contains creator identity, creation date, and editing history
• Can include AI generation disclosures when content is synthetic
• Persists through authorized transformations like resizing or format conversion
• Verified through public key infrastructure to prevent spoofing

The application of hash functions and digital signatures to create mathematically verifiable chains of custody. This underpins the CAI's assertion that provenance claims cannot be forged.

• Uses SHA-256 hashing to create unique content fingerprints
• Employs asymmetric cryptography for signer identity verification
• Creates non-repudiable records that creators cannot later deny
• Enables offline verification without relying on central authorities

A detailed, auditable record of every algorithmic or editorial operation applied to a content asset. CAI manifests capture this lineage to show exactly how content evolved from capture to publication.

• Records actions like crop, resize, filter, and composite operations
• Distinguishes between human edits and AI-generated modifications
• Maintains parent-child relationships between source and derivative assets
• Preserves tool identification showing which software performed each action

The process of embedding a cryptographic hash of a provenance manifest into a public blockchain to provide an immutable, decentralized timestamp. This strengthens CAI provenance by preventing backdated forgery.

• Creates tamper-proof timestamps that no single party can alter
• Leverages public ledgers like Ethereum for distributed trust
• Does not store content on-chain—only hashes for verification
• Provides long-term verifiability independent of any single organization

A W3C standard for cryptographically secure digital credentials that can assert claims about a content creator's identity or organizational affiliation. CAI integrates this to establish trust in attribution.

• Enables privacy-preserving identity claims without exposing personal data
• Supports zero-knowledge proofs for selective disclosure
• Allows decentralized identity verification without central authorities
• Compatible with Decentralized Identifiers (DIDs) for persistent creator identity