There is plenty of misunderstanding about the definition of cryptocurrency. Wikipedia’s well-researched entry on the topic defines “cryptocurrency” as follows (with their links included):

[Cryptocurrency is] a digital asset designed to work as a medium of exchange that uses cryptography to secure its transactions, to control the creation of additional units, and to verify the transfer of assets. Cryptocurrencies are a type of digital currencies, alternative currencies and virtual currencies. Cryptocurrencies use decentralized control as opposed to centralized electronic money and central banking systems. Read More