Original Document, 2008

Bitcoin: A Peer-to-Peer Electronic Cash System

By Satoshi Nakamoto

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Introduction

About the Whitepaper

The Bitcoin whitepaper, published in 2008 by the pseudonymous Satoshi Nakamoto, is the foundational document that introduced the world's first decentralized cryptocurrency.

This revolutionary paper presents an electronic payment system based on cryptographic proof rather than trust in third parties, enabling any two willing parties to transact directly without the need for a trusted intermediary.

9
Pages
18
Years
∞
Impact
Abstract

The Original Abstract

A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending. We propose a solution to the double-spending problem using a peer-to-peer network. The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. As long as a majority of CPU power is controlled by nodes that are not cooperating to attack the network, they'll generate the longest chain and outpace attackers. The network itself requires minimal structure. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will, accepting the longest proof-of-work chain as proof of what happened while they were gone.

Satoshi Nakamoto, abstract of the Bitcoin whitepaper
Table of Contents

What the Whitepaper Covers

The paper is nine pages long and organized into twelve short sections. Here is what each one explains.

  1. Introduction

    Why commerce on the internet still depends on trusted financial institutions, and the cost of that trust.

  2. Transactions

    A coin is defined as a chain of digital signatures. The double-spending problem is stated.

  3. Timestamp Server

    Hashing a block of items and publishing the hash proves the data existed at that time.

  4. Proof-of-Work

    A Hashcash-style proof-of-work makes blocks costly to produce and lets the majority of CPU power decide.

  5. Network

    The steps every node follows to broadcast, validate and chain transactions into blocks.

  6. Incentive

    New coins and transaction fees reward the node that creates a block, encouraging honest behavior.

  7. Reclaiming Disk Space

    Spent transactions can be pruned with a Merkle tree, keeping old blocks small.

  8. Simplified Payment Verification

    Lightweight clients can verify payments by keeping only block headers.

  9. Combining and Splitting Value

    Transactions have multiple inputs and outputs so value can be split and merged.

  10. Privacy

    Public keys stay anonymous while transactions are public, unlike the traditional banking model.

  11. Calculations

    The probability that an attacker catches up with the honest chain, shown to drop exponentially.

  12. Conclusion

    A system for electronic transactions without relying on trust, using a proof-of-work chain.

Document

Read the Original Paper

bitcoin.pdf 184 KB

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Core Ideas

Key Concepts

01

Decentralization

A distributed network with no central authority, maintained by peers worldwide through consensus.

Network
02

Blockchain

An immutable chain of transaction blocks, secured through cryptographic proof-of-work.

Data Structure
03

P2P Transactions

Direct value transfers between users without intermediaries or trusted third parties.

Payment System
04

Proof of Work

Energy-intensive consensus mechanism where miners compete using computational power to secure the network and create new coins.

Security
05

Cryptographic Security

Mathematical algorithms ensuring transaction authenticity and preventing double-spending.

Cryptography
06

Controlled Supply

New coins are issued to block creators as an incentive, like gold miners adding gold to circulation. The 21 million cap was set in the software released in 2009.

Economics
Historical Context

A Vision Over a Century in the Making

Henry Ford's Prophetic Vision

Over 100 years ago, Henry Ford predicted that an "energy currency" would replace gold and stop wars. This vision has now materialized as Bitcoin.

In a 1921 article in the New York Tribune, Ford proposed a revolutionary idea: a currency backed by energy rather than gold. He envisioned a monetary system where the unit of exchange would be based on the universal constant of energy, making it impossible for any single nation to control or manipulate.

"Under the energy currency system the standard would be a certain amount of energy exerted for one hour that would be equal to one dollar. It's simply a case of thinking and calculating in terms different from those laid down to us by the international banking group."

Henry Ford, 1921

Ford believed this system would eliminate the power of bankers to control the world's money supply and prevent wars fought over gold reserves. His vision was remarkably prescient of Bitcoin's proof-of-work mechanism, where computational energy secures the network and creates new currency.

The Bitcoin Connection

Bitcoin realizes Ford's vision through its proof-of-work mining process, where electrical energy is literally converted into digital currency. Miners expend real-world energy (electricity) to solve cryptographic puzzles, securing the network and minting new bitcoins. This creates a direct, measurable link between energy expenditure and monetary value, exactly as Ford envisioned a century ago.

Front page of the New York Tribune, December 4, 1921: Ford Would Replace Gold With Currency Based on Energy

New York Tribune, December 4, 1921

"Ford Would Replace Gold With Currency Based on Energy"

View original at Library of Congress →

1921
Ford proposes energy currency
2008
Bitcoin whitepaper published
2009
Bitcoin network launched
FAQ

Frequently Asked Questions

Who wrote the Bitcoin whitepaper?

The whitepaper is signed by Satoshi Nakamoto, a pseudonym. Satoshi announced the paper on the Cryptography Mailing List on October 31, 2008, released the first Bitcoin software in January 2009, and stopped communicating publicly in 2011. The real identity behind the name has never been confirmed.

How long is the Bitcoin whitepaper?

The whitepaper is nine pages long, about 3,200 words, and is organized into twelve sections plus an abstract and eight references. It can be read in under thirty minutes.

What problem does the whitepaper solve?

It solves the double-spending problem for digital cash without a trusted third party. Transactions are timestamped into a chain of hash-based proof-of-work, so the longest chain becomes the accepted history as long as honest nodes control the majority of CPU power.

Does the whitepaper mention the 21 million bitcoin supply limit?

No. The paper explains that new coins are issued to the creator of each block as an incentive, but it never states a fixed maximum supply. The 21 million cap and the halving schedule were implemented in the Bitcoin software released in January 2009.

Where can I download the original Bitcoin whitepaper PDF?

You can download the original English PDF (184 KB) directly from this page. The same file is hosted at bitcoin.org/bitcoin.pdf, where Satoshi first published it.

Is the Bitcoin whitepaper available in French or Portuguese?

The PDF on this page is the original English version. This website offers a French and a Portuguese summary of the paper, including the abstract, the table of contents, and the key concepts.

"What is needed is an electronic payment system based on cryptographic proof instead of trust, allowing any two willing parties to transact directly with each other without the need for a trusted third party."

Satoshi Nakamoto, Bitcoin Whitepaper