Arash Khamooshi for The New York Times TEHRAN — Stepping from a car into a muddy industrial site in the Iranian desert, a 22-year old European Bitcoin investor raised his voice to be heard over the roar of a gas-fired generator. His Iranian counterparts — a bespectacled information-technology specialist, a self-described ‘‘hard-core Bitcoiner’’ and the businessman running the site — walked their foreign visitor over to gray shipping containers containing thousands of small computers. When...