Proof of work
Proof of work is a computational mechanism requiring demonstrable effort, typically by repeatedly searching for a value whose hash satisfies a difficulty condition.
Real-World Cryptography
Proof of work is a consensus technique in which participants demonstrate computational effort by finding a hash satisfying a difficulty condition.
- How it is used
- Coordinates permissionless Bitcoin consensus by selecting block proposers through computational puzzles.
- How deep it goes
- Explains blocks, nonces, hash difficulty, forks, and chain selection, while stopping short of implementation-level mining details.
- Examples
- Uses Bitcoin block proposals, nonce searches, zero-prefixed digests, competing forks, and an interactive toy blockchain.
- What you can do after
- Evaluate how computational puzzles select miners, resist account-based influence, resolve forks, and impose an energy cost.
The Joy of JavaScript
A computational procedure that requires searching for a value meeting a difficulty condition, often by repeated hashing.
- How it is used
- Uses repeated hashing to make adding blockchain blocks costly while keeping successful results straightforward to verify.
- How deep it goes
- Explains the nonce-and-hash loop and its difficulty prefix, then defers production-grade blockchain implementation.
- Examples
- Demonstrates leading-zero difficulty, nonce mutation, block hashing, block mining, and Worker Threads execution.
- What you can do after
- Build proof-of-work from scratch and run its long computation asynchronously with Node.js Worker Threads.
Related concepts
- hash functionuses · A hash function deterministically maps input data to a value in a bounded output range, commonly for indexing, lookup, comparison, or integrity checking.
- Bitcoinused by · Bitcoin is a decentralized digital currency and cryptocurrency system that records and verifies transactions on a peer-to-peer network using a distributed ledger.
- Byzantine fault-tolerant consensus algorithmalternative to · A Byzantine fault-tolerant consensus algorithm enables distributed participants to agree on a system state despite arbitrary or malicious behavior by some participants.
- mining difficultyconfigured by · Mining difficulty is a threshold or parameter that determines the computational challenge required to produce a valid proof-of-work block.
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