Bitcoin (abbreviation: BTC; sign: ₿) is the first decentralized cryptocurrency. Nodes in the peer-to-peer bitcoin network verify transactions through cryptography and record them in a public distributed ledger, called a blockchain, without central oversight. Consensus between nodes is achieved using a computationally intensive process based on proof of work, called mining, that guarantees the security of the bitcoin blockchain. Mining consumes large quantities of electricity and has been criticized for its