Anthropic published a blog post explaining its watermarking technique for Claude, citing a 2024 Google DeepMind paper. The feature is applied globally to comply with EU AI Act.
Anthropic published a blog post Friday to explain its plan to watermark AI-generated text from its Claude model, addressing concerns that surfaced after the company updated a support page earlier this week. The watermarking is designed to comply with the European Union's AI Act, and the company said it is applying the feature globally because it lacks a way to scope it by region.
The technique draws on a 2024 Google DeepMind paper. When Claude produces text, it makes a series of word choices, some of which are settled by a random number generator. Anthropic said its watermark works as a different type of random number generator. Users who hold a key can detect whether the text follows Claude's pattern of word selection. The company plans to offer an API that lets users and third parties check text for the watermark.
Anthropic's post repeatedly pointed out the limitations. The key only identifies whether text was partly written by Claude, not any other AI model. Longer passages are easier to detect because the model made more word choices. Factual passages and code receive fewer watermarks, the company said, because the wrong word could hurt accuracy or break software.
The watermark does not add hidden characters or change fonts. Light editing probably will not remove it, but a complete rewrite will, according to the post. Some customers told Business Insider they canceled subscriptions over the watermark. Anthropic said it has not seen a trend of cancellations since the announcement.
Watermarks will first be applied to new Anthropic models, then to older ones in the coming months. OpenAI has also said it plans to add watermarks to text, according to a support page updated two weeks ago.
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