Definition
Instead of detecting machine text, prove that content is human (or where it came from).
- C2PA / Content Credentials: a signed manifest binds capture device, edits and AI generation tools to a hash chain; verification = X.509 certificate + hash check. Deployed in Adobe Firefly, DALL·E + Sora, Leica M11-P, Samsung Galaxy S25.
- Personhood credentials: offline issuance, online zero-knowledge proof of unique personhood (e.g. World ID from an iris hash).
Provider side (provenance) + user side (personhood) could together guarantee attribution to humans; technically feasible, politically complicated.