The U.S. Financial Crimes Enforcement Network (FinCEN) noted in a June 2021 report that convertible virtual currencies (CVCs)—another term for cryptocurrencies—have grown to become the currency of choice in a wide range of online illicit activities. Apart from being the preferred form of payment for buying ransomware tools and services, online exploitative material, drugs, and other illegal goods online, CVCs are increasingly used to layer transactions and obfuscate the origin of money derived from criminal activity. Criminals use a number of money-laundering techniques involving cryptocurrencies, including “mixers” and “tumblers” that break the connection between an address (or crypto “wallet”) sending cryptocurrency and the address receiving it.