What Is Cryptocurrency? A cryptocurrency is a virtual/digital currency secured by cryptography, which makes it almost impossible to counterfeit or double-spend. Many cryptocurrencies are decentralized networks based on blockchain technology—a distributed ledger enforced by a disparate network of computers. A fundamental feature of cryptocurrencies is that they are usually not issued by any central authority, rendering them in theory immune to governmental control or manipulation. Cryptocurrencies can be mined, purchased from cryptocurrency exchanges, or rewarded for work done on a blockchain. Not all e-commerce