Bitcoin is a decentralized digital currency that may be purchased, traded, and traded without intermediary like a bank. Bitcoin is built on the blockchain, which is a distributed digital ledger. Wei Dai suggested a new kind of money that relies on cryptography rather than a central authority to oversee its production and transactions on the cypherpunks mailing list in 1998. Bitcoin was the first application of that notion. In 2009, Satoshi Nakamoto sent out the first Bitcoin specification and proof of concept to a cryptography mailing group.