Anthropic to Globally Deploy Invisible Text Watermarks for Claude to Comply with EU AI Act

新智元 · wechat · 2026-08-11

In response to the transparency requirements of the EU AI Act (Article 50), Anthropic has announced it will tag outputs across all Claude products globally. This marks the first large-scale deployment of text watermarks by a mainstream AI company.

Two-Layer Tagging Technology

The first layer is a Text Watermark: created by introducing an invisible statistical bias during Token generation. This watermark persists through copy-pasting, and the company claims it does not affect text quality or readability. The second layer is File Provenance Metadata: attaching C2PA digital signatures to generated files (like images) to mark origin and detect tampering.

Limitations and Controversies

Anthropic cautions that the watermark is not foolproof: its presence doesn't mean Claude is the sole original author (e.g., if used for translation or polishing), and heavy rewriting or very short texts can render it undetectable. Conversely, the absence of a watermark doesn't guarantee human authorship. This move has sparked concerns among users regarding source neutrality, with some paid subscribers needing untraceable content expressing dissatisfaction. This could indirectly boost the appeal of open-source models.

Related event: Claude Rolls Out Invisible Watermarks and Metadata, Sparking Compliance and Tech Debates(115 posts)→

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