Cryptocurrencies are privately developed and maintained digital products for making and accepting financial payments and protecting wealth. They are intended to replace government currencies, such as the dollar-based currency provided by the U.S. Treasury. By far the most widely accepted and used cryptocurrency is Bitcoin, introduced in 2009. Millions of individuals and entities worldwide hold or have held investments in Bitcoin, and tens or hundreds of thousands of individuals and entities engage in Bitcoin “mining” (the process of creating new Bitcoin by solving computational puzzles).