Cryptocurrency is an electronic currency that can be used on a decentralized computer network. First introduced in 2009 with Bitcoin, cryptocurrency allows money transfers, online payments while guaranteeing a minimum of anonymity on the Internet. To do this, users go through a "Blockchain". This decentralized encryption network allows actions to be performed without going through a third party. Cryptocurrencies are stored in "wallets". A so-called "hot" wallet is permanently connected to the Internet and is used to pay for purchases in real time. They also use so-called "cold" wallets, which are not connected to the Internet. They require to be unlocked by their owner using a private key before they can accept a transaction. Many crypto-currencies are created each year. In 2018, Venezuelan President Nicolas Maduro created the petro, to bypass American sanctions.