A cryptocurrency is a digital or virtual currency that is designed to be used as a medium of exchange. A subset of digital currencies, cryptocurrency uses cryptography to secure the creation and transactions of its units. Bitcoin was first of its kind, and these currencies use decentralized control which means no bank or government has control over it. It uses blockchain, a public ledger that records transactions. As of December 2017, there were over 1377(+) digital currencies in existence & total market capitalization of cryptocurrencies is bigger than 600 billion $ and record high daily volume is larger than 50 billion $.