The Bitcoin white paper

On 31 October 2008, someone going by Satoshi Nakamoto×Satoshi NakamotoPseudonym of the creator (or collective) behind Bitcoin. Active on forums from 2008 to 2011, then vanished without revealing any identity. Holds roughly 1.1 million BTC that have never moved.See in the lexicon → posted a nine-page document to a cryptography mailing list, titled "Bitcoin: A Peer-to-Peer Electronic Cash System". This founding text describes, without a single line of code, the complete idea of Bitcoin: electronic cash that moves directly from one person to another, with no bank or intermediary, and that solves the double-spending problem through a network and proof-of-work.

Here is what the document contains, section by section, followed by a link to the original.

The document, section by section

1. Introduction. Commerce on the internet relies almost entirely on financial institutions acting as trusted third parties. That model has inherent weaknesses: reversible transactions, mediation costs, fraud. Satoshi×Satoshi (sat)The smallest unit of bitcoin. 1 BTC = 100 million satoshis. Named after the creator. In 2026, talking in sats becomes common as the price of one BTC rises.See in the lexicon → proposes a payment system based on cryptographic proof instead of trust.

2. Transactions. A coin is defined as a chain of digital signatures: each owner transfers it by signing a hash×HashFunction that turns data of any size into a fixed-size fingerprint. The same input always yields the same output, but you cannot go back from output to input.See in the lexicon → of the previous transaction and the next owner's public key×Public keyNumber derived mathematically from the private key, used to build a Bitcoin address. Can be shared freely.See in the lexicon →. One problem remains: the recipient cannot tell on their own whether the coin was already spent elsewhere.

3. Timestamp server. The solution starts by publicly dating transactions. A timestamp server takes a hash of a batch of items and publishes it; each timestamp includes the previous one, forming a chain in which every link reinforces the ones before.

4. Proof-of-work. To do this without a central authority, the network uses proof-of-work: searching for a value whose hash starts with enough zero bits. The effort is costly to produce, instant to check. "One CPU, one vote": the longest chain embodies the majority decision.

5. Network. In practice: transactions are broadcast to all nodes, each node×NodeComputer that runs the Bitcoin software and takes part in the network by validating blocks and transactions. A « full node » keeps a complete copy of the blockchain.See in the lexicon → gathers them into a block and looks for the proof-of-work, then broadcasts the solved block. Others accept it if everything is valid and build the next block on top. The longest chain wins.

6. Incentive. The first transaction in a block mints a new coin for its creator: the reward that motivates securing the network and the way coins are issued without a central bank. Transaction fees×Transaction feesAmount paid to miners so they include your transaction in a block. Expressed in satoshis per virtual byte (sat/vB). Varies with network congestion.See in the lexicon → add to it. The incentive makes honesty more profitable than attacking.

7. Reclaiming disk space. Once a coin is buried under enough blocks, old transactions can be forgotten without breaking the chain, thanks to a Merkle tree whose root alone is kept in the block.

8. Simplified verification (SPV). A payment can be checked without downloading everything: all you need are block headers and the proof (Merkle branch) linking the transaction to a block. This is the principle behind lightweight wallets.

9. Combining and splitting value. A transaction can have several inputs and outputs: you combine small amounts or split a larger one, usually with two outputs (the payment and the change).

10. Privacy. Transactions are public, but keys carry no name. Privacy rests on that anonymity: amounts are seen moving without linking keys to identities, especially if a fresh key is used for each transaction.

11. Calculations. Satoshi works out the probability that an attacker catches up with the honest chain: it falls exponentially with the number of confirmations. Past a few blocks, rewriting history becomes out of reach. Hence the habit of waiting for several confirmations.

12. Conclusion. The paper proposes a system for transactions without a trusted third party: coins born from signatures, and a peer-to-peer network that, through proof-of-work, keeps a public history that cannot be forged as long as honest nodes hold the majority of computing power. All of Bitcoin's strength lies in that simplicity.