Bitcoin Whitepaper Glossary

Double-Spending

The fraudulent attempt to spend the same digital currency unit more than once. The Bitcoin Whitepaper's primary problem statement. Solved by the distributed timestamp and proof-of-work chain.

Proof-of-Work

A mechanism requiring a participant to expend computational effort to produce a valid block. The result is easy for the network to verify but expensive to produce, making history rewriting economically impractical.

Hash / SHA-256

A cryptographic function that converts any input into a fixed-length output. Changing even one character of the input produces a completely different hash. Bitcoin uses SHA-256 for block hashing.

Blockchain

The chain of linked blocks produced by the Bitcoin network. Each block contains a hash of the previous block, creating an ordered, tamper-resistant ledger of transactions.

Node

Any participant in the Bitcoin network that validates and relays transactions and blocks. Full nodes store the complete blockchain. Lightweight nodes store only block headers.

Merkle Tree

A data structure used in the whitepaper to efficiently summarise all transactions in a block. Only the Merkle root needs to be stored in the block header, allowing old transaction data to be pruned.

Timestamp Server

The whitepaper's term for the distributed system that records when transactions occurred by hashing them into the blockchain. Each block serves as a timestamp for the transactions it contains.

Nonce

A "number used once" that miners vary when searching for a valid proof-of-work. The miner iterates the nonce until the block hash meets the target difficulty.

Peer-to-Peer (P2P)

A network architecture with no central server. Participants connect directly to each other and share responsibility for storing and validating data.

Digital Signature

A cryptographic proof that a message or transaction was created by a specific private key holder. Used in Bitcoin to prove ownership of coins being spent.

Public Key

The shareable part of a cryptographic key pair. A Bitcoin address is derived from a public key. Others use your public key to verify your digital signatures.

Satoshi Nakamoto

The pseudonymous author of the Bitcoin Whitepaper. Their true identity has never been confirmed. Satoshi communicated publicly until approximately 2010.