Acryptocurrency(orcrypto currency) is adigital assetdesigned to work as amedium of exchangethat usesstrong cryptographyto secure financial transactions, control the creation of additional units, and verify the transfer of assets.[1][2][3]Cryptocurrencies usedecentralized controlas opposed to centralized digital currency andcentral bankingsystems.[4] The decentralized control of each cryptocurrency works throughdistributed ledgertechnology, typically ablockchain, that serves as a public financial transaction database.[5] Bitcoin, first released as open-source software in 2009, is generally considered the first decentralized cryptocurrency.[6]Since the release of bitcoin, over 4,000altcoins(alternative variants of bitcoin, or other cryptocurrencies) have been created. :o