C2PA Standard for Audio: A Provenance Guide

What is the C2PA standard?

The C2PA standard — the Coalition for Content Provenance and Authenticity content provenance specification — defines a cryptographic manifest that travels with a media file, describing how it was produced, edited, and signed. It is the same standard adopted by Adobe, Microsoft, the BBC, and the Content Authenticity Initiative for images and video. AmaQnA extends it to synthesized audio.

Manifest fields we emit

Every clip AmaQnA generates carries a manifest with:

• c2pa.actions — the AI actions taken (e.g. generated by, voice cloned from consented sample).
• c2pa.ingredients — the host's approved answer text and the voice-model reference.
• c2pa.claim_generator — AmaQnA/1.0 with the model IDs of the drafter and synthesizer.
• c2pa.signature — Ed25519 signature bound to the host's public key.

ID3 tagging for audio

Since MP3 and M4A players ignore sidecar manifests, we also stamp an ID3v2 TXXX:C2PA frame with a base64-encoded copy of the manifest hash. Podcast apps, DAWs, and forensics tools can read this frame without a specialized library — the round-trip check still verifies against the sidecar.

EU AI Act & disclosure

The EU AI Act's Article 50 requires that synthetic audio be labelled in a machine-readable way. A signed C2PA manifest is the canonical way to satisfy that requirement. AmaQnA additionally prepends an audible AI disclosure to every clip so end-listeners are informed even when the manifest is stripped.

Verifying an AmaQnA clip

Any C2PA-compatible verifier (the c2patool CLI, Content Credentials browser extension, etc.) will show the manifest, the signing host, and the chain of actions. If the audio is re-encoded or edited without preserving the manifest, the verifier reports the tampering — a signal downstream publishers can use before syndicating.