Bitmain, the leading Chinese manufacturer of Bitcoin mining application-specific integrated circuits (ASICs), is facing scrutiny in the United States over potential national security risks. According to a Bloomberg report published on Friday, November 21, 2025, the U.S. Department of Homeland Security (DHS) is leading an investigation, dubbed "Operation Red Sunset," to determine whether Bitmain's hardware could be remotely controlled for espionage or used to sabotage the U.S. power grid.
The investigation involves agencies including the Federal Communications Commission and the National Security Council. U.S. officials have reportedly conducted physical inspections of seized Bitmain equipment at ports, testing their chips and firmware for malicious capabilities. The probe also examined potential tariff violations and whether the company's ties to the Chinese Communist Party (CCP) create unacceptable risks. In some instances, investigators disassembled Bitmain ASICs to look for malicious capabilities. However, officials have not disclosed the outcome of the investigation.
Concerns over Chinese-owned Bitcoin mines intensified after a New York Times investigation reported that several facilities with ties to the Chinese Communist Party were operating near critical U.S. infrastructure, including one next to a Microsoft data center supporting the Pentagon and near an Air Force nuclear missile base in Cheyenne, Wyoming. Many of these operations were equipped with Bitmain machines. Furthermore, a Senate Intelligence Committee report in July stated that Bitmain's devices could be manipulated from China and posed "several disturbing vulnerabilities" to the U.S. The Senate report directly linked Bitmain's operations to the CCP, warning that its machines "have the capability to be remotely [controlled]".
Bitmain has denied any remote-control capabilities and said it has no knowledge of the investigation, calling the allegations "unequivocally false". The company added that it "strictly complies with U.S. and applicable laws and regulations and has never engaged in activities that pose risks to U.S. national security". Bitmain attributed past equipment detentions to routine Federal Communications Commission concerns, stating that "nothing out of the ordinary was found".
The investigation could have far-reaching consequences for the U.S. crypto mining industry, as Bitmain controls a significant portion of the Bitcoin mining ASIC market. According to a Cambridge report, Bitmain controls over 80% of the Bitcoin mining ASIC market. Bitmain and the second-largest manufacturer, MicroBT, both based in mainland China, control 97% of the market share. This raises long-term risks for operators dependent on foreign-made equipment.
The investigation underscores how U.S. regulators increasingly view mining hardware as part of national critical infrastructure. This secret Bitmain investigation serves as a wake-up call for the entire cryptocurrency industry. It underscores the importance of secure, transparent hardware supply chains and the growing intersection between digital assets and national security.
