In 2008, money became more complicated when something called 'cryptocurrency' was invented, and in a short span of time swept into the global consciousness. The name was bitcoin and it was either the brave new future of money or a menace to the world economy. The core innovation is a technology called blockchain, capable of transforming not just how money works but many other things too, from the law to democracy. Technology is sweeping out widely into the future with Internet-aware appliances, decentralised banks and even autonomous corporations. This Instant Expert Guide introduces this new concept of money as a digital technology and the book travels from the dark alleys of the Internet to the penthouses of global finance. We get into details of cryptographic mathematics, and explore the often strange bitcoin subculture, talk about what makes the money in our pockets, what makes the economies of nations, and about what might change these notions for good. Digital currencies conceived by computer hackers and cryptographers represent a completely new sort of financial transaction that could soon become mainstream. Are we now moving away from the backbone for a digital currency and into other core concepts of society - identity, ownership and even the rule of law?