Researchers Extract Reasoning Traces from Major AI APIs
A new paper demonstrates large-scale extraction of raw reasoning traces from OpenAI, Anthropic, and Gemini models via API flaws.
Maksym Andriushchenko and coauthors released a 116-page paper detailing extraction of encrypted chain-of-thought outputs from OpenAI, Anthropic, and Gemini APIs. Multiple researchers, including Timothée Chauvin and Alexander Panfilov, posted that the encryption was implemented poorly enough to allow recovery of hidden reasoning tokens at scale. The extracted token counts matched billed thinking tokens one-to-one on most tested prompts. Commenters noted the work also surfaces examples of illegible reasoning, especially from GPT models, and discussed related risks such as distillation attacks and credential extraction. The site stolen-thoughts.com presents the core finding that encrypted blocks are interchangeable across sessions, users, and models.
We can finally talk about it: We found a way to extract hidden reasoning of frontier models using a vulnerability in the APIs of every frontier AI company. We verified that our reasoning token count matches billed API thinking tokens 1:1 for most of the prompts we queried.


