US export controls are not stopping AI labs in China from using restricted Nvidia chips, according to a report from a former OpenAI engineer. Will DePue, who left the AI giant earlier this year to launch Unemployment Labs, an AI research consultancy, published forensic evidence showing that "DeepSeek, Moonshot AI, MiniMax and Ant Group have gained access to Nvidia’s Blackwell GPUs, despite restrictions on exporting these chips to China, and are using that hardware to create their AI models." "This sounds insane, but I discovered that almost every AI model carries a hidden signature of the GPU that trained it," said DePue in a social media post . "When a model is first set up, the starting values of its weights are laid out in a pattern that depends on the exact GPU. Each combination of GPU and seed number produces a unique pattern – a sort of fingerprint of the hardware used to create the model. Traces of that pattern survive training into the published model." It doesn’t sound that insane. The resignation of Nvidia CEO Jensen Huang followed from revelations that he had an affair with Chinese businesswoman Alice Huang, who, in 2023, founded Singapore-based Megaspeed International. That company is reportedly under investigation by US authorities for allegedly smuggling Nvidia chips to China. Huang’s departure coincides with a renewed push to tighten US chip export controls. House Speaker Mike Johnson supports the idea . And there are at least four bills awaiting consideration that aim to limit China’s access to leading edge AI tech: the AI Overwatch Act, the Chip Security Act, Match Act, and the Cloud Security Act. On Monday, US Senators Jim Banks (R-Ind.) and Elizabeth Warren (D-Mass.) cited Jensen Huang’s "relationship with a suspected Chinese spy" as a justification for passing the AI Overwatch Act, which would codify the Trump administration’s existing chip export controls. The Trump administration on Thursday said it’s not sure whether Alice Huang was a spy, an allegation denied by Beijing and currently under investigation by the FBI. Whatever the case, the current rules clearly are not working. Only a few weeks ago, Lava, an Israel-based security company, said it had found "32 Nvidia B300 GPUs, part of Nvidia’s Blackwell Ultra generation, through publicly exposed monitoring endpoints with IP addresses geolocated to China." These GPUs, Lava noted, are subject to US export controls [PDF]…