WHAT IS THE REAL REASON FOR WATERMARKING AI-GENERATED CONTENT
Dr Fabio de Oliveira asks what AI watermarking really proves. As invisible markers become part of AI regulation, he argues that detecting AI involvement is not the same as proving AI authorship.
The debate about watermarking AI-generated content has become more significant. On 14 August 2026, Anthropic announced that future Claude models will generate text with an invisible statistical watermark in response to transparency requirements under the EU AI Act. Anthropic also makes an important distinction: a watermark may indicate that Claude was involved in producing a piece of text, but it does not establish who authored it. That distinction could become one of the most consequential questions in generative AI governance because watermarking can indicate involvement but cannot prove authorship.
What exactly is an AI text watermark?
A statistical watermark is not an invisible signature attached to a document. There are no secret characters hidden between words. Instead, the watermark is created while the text is being generated. Large Language Models produce text by repeatedly selecting the next token from a range of possibilities. Sometimes there is an obvious continuation. At other times, several words could work equally well. Take a simple sentence:
