Without cryptography, the entire internet might still be that small, open, decentralized and freely accessible playing field for nerds, gamers, scientists and hackers, with no contradiction between the public and the private and no need to ensure the identity and authenticity of every participant. At the same time, commerce and e-commerce would not be possible. Cryptography is the technology that enables secure transactions between participants who do not know one another. The value of a functioning cryptocurrency lies solely in its pseudonymous and decentralized form of transaction. A cryptocurrency seems a good solution when very many people, for very good reasons, cannot trust one another yet still want to do business together. Cryptos guarantee a market outside social bonds and obligations; they are the money of libertarian ideology. The blockchains, as an eternal ledger of past transactions, are their histories.