Cryptocurrencies have attracted the attention of regulators worldwide. Cryptocurrencies are digital networks that use cryptography-code writing-to carry out transactions securely. The first cryptocurrency, Bitcoin, launched in 2009. Since then, hundreds of other cryptocurrencies have emerged and billions of dollars have flowed into cryptocurrency systems. Supporters believe that cryptocurrencies can increase the privacy of online transactions and serve as a more durable and secure form of money than existing fiat currencies.