Bitcoin's still anonymous inventor, who went by the pseudonym Satoshi Nakamoto, figured out a completely new way for a decentralized network to reach a consensus about a shared transaction ledger. This innovation made possible the kind of fully decentralized electronic payment systems that cypherpunks had dreamed about for decades. //

One challenge is how to introduce new coins into the system. Obviously a viable payment network needs some way to create new coins, but if you let anyone create new coins whenever they want, the currency will quickly become worthless. //

The second challenge is known as the double-spending problem. The rules of bitcoin say that each transaction output can only be spent once. If someone tries to spend the same output twice, the bitcoin community needs some way to detect this double-spending attempt and reject the later transaction. //

bitcoin inventor Satoshi Nakamoto wanted to build a network that wasn't controlled up by any single organization.

So Nakamoto invented a shared ledger called the blockchain that is maintained by computers, called nodes, operating on a peer-to-peer network. Thousands of computers around the world keep separate copies of the entire blockchain, storing every transaction that has happened since the network was launched in 2009. The network rewards nodes who help to create the blockchain by allowing them to create new bitcoins—solving the coin-distribution problem while simultaneously creating an incentive to help solve the ledger-updating problem.