Bitcoin 15 keychain

Bitcoin is a worldwide cryptocurrency and digital payment system called the first decentralized digital currency, as the system works without a central repository or single administrator. It was invented by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software in 2009.The system is peer-to-peer, and transactions take place between users directly, without an intermediary. These transactions are verified by network nodes and recorded in a public distributed ledger called a blockchain.