Open AI's memo to the House

"China's distillation methods over the last year have become more sophisticated, moving beyond chain-of-thought (CoT) extraction to multi-stage operations. These include synthetic-data generation, large-scale data cleaning, and other stealthy methods.

"OpenAI also notes that it has invested in stronger detections to prevent unauthorized distillation. It bans accounts that violate its terms of service and proactively removes users who appear to be attempting to distill its models. Still, the company admits that it alone can't solve the model distillation problem.

"It's going to take an ecosystem security approach to protect against distillation, and this will require some US government assistance, OpenAI says. 

"'It is not enough for any one lab to harden its protection because adversaries will simply default to the least protected provider,' according to the memo (pdf). 

"The AI company also suggests that US government policy may be helpful when it comes to sharing information and intelligence, and working with the industry to develop best practices on distillation defenses. 

"OpenAI also called on Congress to close API router loopholes that allow DeepSeek and other competitors to access US models, and to restrict adversary access to US compute and cloud infrastructure."