EU AI Act Article 50 — Watermarking Pack

1 · Why this pack exists

EU AI Act Article 50 (Transparency obligations for providers and deployers of certain AI systems) requires that:

1. Providers of GPAI systems (general-purpose AI, including foundation models) ensure technical solutions allow marking of AI-generated output (machine-readable + detectable).
2. Deployers of AI systems that generate or manipulate image / audio / video / text content disclose AI generation to natural persons.
3. The marking is effective, interoperable, robust, and reliable as far as technically feasible, taking into account specificities and limitations of the content type and implementation cost.

Article 50 enters into force 2026-08-02. From that date, any GPAI provider placing models on the EU market must comply. DEFONEOS's sovereign weight family (SOV3-small, SOV3-large, Liquid-KAN-MoE, Sovereign-Defence-secured) are all in scope when deployed to EU buyers.

2 · The 2 watermarking methods (machine-readable + user-visible)

Method 1 · Machine-readable (C2PA-style)

Every DEFONEOS output (text / image / audio / video) carries an embedded machine-readable manifest signed by the model's Ed25519 SIGIL key. The manifest contains:

{
  "manifest_id": "WATERMARK-2026-08-02-abc123",
  "version": "1.0",
  "issuer": "defoneos-sovereign-runtime",
  "model_id": "sov3-small-9b",
  "model_version": "v0.95.1",
  "build_sha256": "abc123...",
  "content_type": "text | image | audio | video",
  "content_sha256": "...",
  "created_at": "2026-08-02T...",
  "c2pa_claim_generator": "DEFONEOS-WATERMARK-v1",
  "c2pa_assertions": [
    {"label": "c2pa.ai_generative_training", "value": "trained_with_synthetic_data_consent"},
    {"label": "c2pa.ai_generative_inference", "value": "generated_by_defoneos_sovereign_runtime"},
    {"label": "defoneos.bft_council_vote", "value": "BFT-1247-28-5-0"},
    {"label": "defoneos.sigil_chain", "value": "..."}
  ],
  "ed25519_sig": "...",
  "public_verify_url": "csoai.org/verify/watermark/{manifest_id}"
}

Method 2 · User-visible label

Every DEFONEOS output also carries a user-visible label, format:

"[AI-generated by {model_name} · {timestamp} · {build_sha256}]"

For text: prepended to the response. For images: stamped in the bottom-right corner (24px height, semi-transparent, monospace). For audio: TTS-synthesised announcement at start ("This audio was generated by ..."). For video: 3-second title card at start + persistent watermark overlay.

3 · The 5 robustness test classes

DEFONEOS's watermark is tested against 5 robustness classes. Target: ≥95% watermark survives each class (composite target across all 5).

4 · The 5 named cross-walks

5 · The 7 implementation surfaces

Watermarking is applied at 7 surfaces in the DEFONEOS runtime:

1. Text generation — machine-readable manifest embedded in response metadata + user-visible label prepended
2. Image generation — C2PA manifest embedded in PNG/JPG metadata + visible watermark overlay (24px corner)
3. Audio synthesis — C2PA manifest in MP3/WAV metadata + 3-second announcement at start
4. Video synthesis — C2PA manifest in MP4 metadata + 3-second title card + persistent overlay
5. Code generation — header comment with machine-readable ID + build SHA + visible attribution
6. Structured data (JSON / CSV / XML) — manifest embedded in metadata field + visible header row
7. API responses (REST / GraphQL) — manifest in response header `X-DEFONEOS-Watermark` + body `_meta.watermark`

6 · Public verification API (the 30-second trust root)

Any third party can verify a DEFONEOS watermark in <30 seconds:

1. Extract watermark ID from output (manifest ID + build SHA visible)
2. Visit csoai.org/verify/watermark/{manifest_id}
3. Read the public record: model · version · build · timestamp · BFT vote · sigil chain

{
  "watermark_id": "WATERMARK-2026-08-02-abc123",
  "status": "valid",
  "model": "sov3-small-9b",
  "model_version": "v0.95.1",
  "build_sha256": "abc123...",
  "created_at": "2026-08-02T...",
  "bft_council_vote": "BFT-1247-28-5-0",
  "issuer_signature": "valid (Ed25519)",
  "public_endpoint": "csoai.org/verify/watermark/WATERMARK-2026-08-02-abc123"
}

7 · The 5 buyer-side deployment scenarios

8 · Pre-2026-08-02 compliance work

9 · Cross-walk to existing DEFONEOS artefacts

10 · The 5 Anti-Patterns (Watermarking Disasters We Refuse)

1. No "watermark trivially removable." 5-class robustness test battery required; ≥95% survival.
2. No "user-visible label hidden in fine print." 24px minimum height on images, 3-second announcement in audio, 3-second title card in video.
3. No "machine-readable manifest unsigned." Ed25519 SIGIL mandatory.
4. No "buyer opt-out without disclosure." Buyers may suppress user-visible label for internal use, but manifest always present.
5. No "no public verification." csoai.org/verify/watermark always live.

11 · Next Steps

1. Verify this pack hash: curl https://csoai.org/defoneos-mod-ai-act-art-50-watermarking-pack.html | shasum -a 256
2. Inspect a sample watermark: csoai.org/verify/watermark/sample
3. Browse EU AI Act compliance summary: defoneos-mod-eu-cyber-resilience-act-readiness.html
4. Request DEFONEOS watermarking integration for your deployment: commercial@csoai.org
5. Subscribe to watermarking advisories: csoai.org/advisories/subscribe