Cryptocurrencies in general and bitcoin in particular are a new and poorly understood phenomenon. Basically, the public is content with rumors or frankly advertising texts. True, a couple of books about bitcoins have been published in Russia - for currency speculators, with stories of how to make money and silences about how not to lose your own money. And no one has explored cryptocurrencies comprehensively. Before the book was written and published, which you hold in your hands.