test-user 74618b91a7 feat: detect xAI/Grok EXIF signature; refresh watermarking landscape (v0.5.5) ...

xAI Grok (Aurora) images carry no C2PA/SynthID/IPTC -- their only provenance
signal is an EXIF pair: ImageDescription "Signature: <base64>" + a UUID Artist.
Verified stable across 3 genuine generations (a real download previously read
as unknown / "no AI metadata").

- metadata.xai_signature(): matches the Signature blob + UUID Artist pair;
  wired into has_ai_metadata, get_ai_metadata, and identify (platform
  "xAI (Grok / Aurora)").
- data/samples/grok-1.jpg: real Grok fixture (neutral content; the Artist UUID
  is the public image id, not PII).
- Tests: synthetic-fixture unit tests, real-sample assertion, identify
  integration (322 passing).

Docs (research refresh, May 2026):
- C2PA 2.4 Durable Content Credentials (soft-binding re-discovery after the
  embedded manifest is stripped).
- New AI-labeling laws, primary-source verified: EU AI Act Art 50 (2026-08-02),
  South Korea AI Framework Act Art 31(3), California AB 853.
- Hedge removal claims: defeating the SynthID verifier is not forensic
  invisibility (arXiv:2605.09203); cite SynthID-Image (arXiv:2510.09263).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

2026-05-26 14:14:35 -07:00

..

samples

feat: detect xAI/Grok EXIF signature; refresh watermarking landscape (v0.5.5)

2026-05-26 14:14:35 -07:00

synthid_corpus

Track the labeled SynthID corpus; complete metadata-source test coverage

2026-05-25 14:46:47 -07:00