Cryptocurrencies are independent of conventional, governmental currency systems such as the Euro or the Dollar. Popular cryptocurrencies are, for example, Bitcoin, Ether, Bitcoin Cash and Ripple. For cryptocurrencies, the right to ownership is controlled through the possession of computer-generated keys. Payments are cryptographically legitimized and processed via a network of computers with equal rights – without the need for a bank. The administration is based on a decentralized, synchronized accounting system, the so-called blockchain.