Bitcoin was first mined in 2009 on a standard laptop CPU. Within a few years, miners had migrated to graphics processing units for their superior hashing efficiency, then to field-programmable gate arrays, and by 2013 to application-specific integrated circuits purpose-built for Bitcoin mining. Each hardware generation rendered the previous one unprofitable, because the proof-of-work mechanism adjusts difficulty to maintain a ten-minute block interval regardless of total network computing power. Better hardware does not reduce the network’s energy consumption; it raises the difficulty floor, and the total energy expenditure grows with investment.

Bitmain, a privately held Chinese company, controls an estimated 80% of the global market for cryptocurrency mining hardware. The application-specific integrated circuits it manufactures — the ASICs that power the overwhelming majority of Bitcoin mining operations worldwide — are physically present inside data centers scattered across the United States, operating at sustained high power loads, networked to the internet, and in many cases located in states with significant military or defense infrastructure. In November 2025, the Department of Homeland Security opened a formal investigation into whether Bitmain’s equipment can be remotely controlled for surveillance, espionage, or grid disruption purposes.