Block Inc., the financial-technology company run by Twitter co-founder Jack Dorsey, has introduced what it says is the first Bitcoin mining application-specific integrated circuit (ASIC) designed and manufactured in the United States. The chip, dubbed “Proto,” represents the company’s initial commercial hardware release aimed at the digital-asset mining market. Dorsey described Proto as the “greatest bitcoin miner of all time,” highlighting an energy efficiency of 14.1 joules per terahash. If validated in large-scale deployment, that metric would place the device among the most power-efficient machines currently available, challenging industry leaders such as Bitmain and MicroBT that manufacture primarily in China. A domestically produced ASIC could reduce U.S. miners’ dependence on Asian supply chains and help diversify control of the Bitcoin network’s computing power, an issue advocates have long tied to decentralization and national security. Block has not yet disclosed pricing, production volumes or a shipping timeline.