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Forks (Bitcoin)

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Forks (Bitcoin)

Tags: consensus, soft fork, hard fork, chain split

Accidental forks (chain splits)

When two miners find valid blocks close together, different parts of the network may see different tips briefly. Bitcoin resolves this with Nakamoto consensus: nodes follow the valid chain with the most accumulated Proof of Work (often called the “longest” or “heaviest” chain). The losing block becomes stale; its transactions return to the mempool if they do not conflict with the winning chain.

This kind of fork is a normal network event, not a change to protocol rules.

Source: raw/Books/izobretaem-bitkoin/glava-5.md

Soft forks vs hard forks (rule changes)

Soft fork: new rules are stricter (or additive in a backward-compatible way). Older nodes still accept blocks produced under the new rules as valid within their own rule set. Example from the sources: the 1 MB block size limit introduced in September 2010 — old nodes still saw smaller blocks as valid.

Hard fork: rules expand or change in a way that makes previously invalid blocks valid (or vice versa in incompatible ways). Nodes that do not upgrade reject blocks from the new rule set, so persistent disagreement yields two chains and effectively two assets if both survive economically.

The sources give Bitcoin Cash (August 2017) as a hard fork driven by disagreement over block space and fees: proponents of larger blocks forked; the majority of validating nodes and economic activity remained on the chain that kept the 1 MB (weight-based) constraint, which the wiki treats as Bitcoin.

Source: raw/Books/izobretaem-bitkoin/glava-8.md

Governance reality

Forks illustrate that “Bitcoin” is what users, merchants, and node operators run and accept — not what any single author, miner, or company declares. Hard forks without broad consensus produce altcoins that share history up to the split; they do not change the 21M cap on the chain that enforces it.

Sources: raw/Books/izobretaem-bitkoin/glava-8.md, raw/Books/vojna-za-razmer-bloka/ (blocksize war narrative)

Sources

Glossary | governance | Proof of Work | BIP | blockchain | mempool

  • governance — nodes, miners, developers, users
  • bip — how upgrades are proposed and activated
  • blocksize-war — 2015–2017 conflict in outline
  • blocksize-war — Jonathan Bier’s account
  • segwit — major soft fork in that era

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