C2PA 2.4 manifests, signed at scale.

The Coalition for Content Provenance and Authenticity (C2PA) defines how digital content records its origin and edit history through cryptographically signed manifests. Verbitas builds, signs, embeds, parses, and verifies them as part of a layered provenance stack—not as a single “authenticity” verdict.

What Verbitas implements

  • Manifest builder — JUMBF-encoded claim structures with typed assertions
  • RemoteSigner — COSE_Sign1 via an isolated KMS signer; only the signer calls KMS
  • Embedder — JPEG APP11, PNG caBX, and sidecar manifests
  • Parser — 32 MiB cap, CBOR depth ≤ 32, depth-bomb protection
  • Verifier — multi-signal result using the closed VerificationStatus enum

Supported assertions

Assertion Description
ai_generated Content is AI-generated
generator Name of the generating system
model Model identifier used for generation
prompt_hash SHA-256 of the generation prompt
created_at ISO 8601 creation timestamp
editor Editor identity (editorial recipes)
published Publication record (editorial recipes)
exif EXIF metadata preservation
curl -X POST https://api.verbitas.io/v1/sign \
  -H "Authorization: Bearer $VERBITAS_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -F "[email protected]" \
  -F "recipe=image-genai-v1"

# Signals typically include c2pa + watermark layer (e.g. trustmark)

Trust list

Verbitas maintains a configurable trust list of signing certificate authorities. Enterprise tenants may configure custom trust lists via the tenant API.

We do not prove that depicted events are “true”; we expose explainable verification states. See docs for verification states and compliance positioning.

Layer cryptographic provenance with watermarks.

C2PA plus durable watermarking and soft-binding give you overlapping signals—not a single point of failure.