A purely peer-to-peer version of the electronic cash system that will allow online payments to be sent directly from one party to another without going through a financial institution

While digital signatures offer some solutions, the main benefits of electronic payments are offset when a trusted third party is still needed to prevent double-spending. We propose a solution that uses a peer-to-peer network to solve the problem of double spending. The peer-to-peer network will timestamp each transaction by entering the hashed data of the transaction into an extending, hash-based proof-of-work chain that is impossible to change without a complete redo. The longest chain is used to prove the events that have been witnessed and their order, and on the other hand, to prove that it comes from the largest pool of CPU hashpower. As long as the vast majority of CPU computing power is controlled by benign nodes – that is, they don't cooperate with those who try to attack the network – then benign nodes will generate the longest chain and outpace attackers. The network itself needs a minimal structure. Information will be disseminated on the basis of best efforts, and nodes will come and go freely; However, when joining, it is always necessary to accept the longest chain of proof-of-work as proof of everything that happened during the period in which they were not involved.