This paper proposes Bitcoin, a peer-to-peer electronic cash system eliminating the need for trusted third parties in online transactions. It uses a distributed timestamp server based on a proof-of-work system to create a secure, chronological record of transactions. The system's security relies on honest nodes controlling the majority of computing power to maintain the longest transaction chain. This chain serves as proof of the transaction order, preventing double-spending. Privacy is maintained through the use of anonymous public keys. Mathematical calculations demonstrate the system's resilience against attacks.