{
  "schema_version": "1.0",
  "title": "A component-provenance map",
  "description": "The table distinguishes a precursor’s contribution from the additional role it plays inside Bitcoin.",
  "type": "table",
  "columns": [
    "Component",
    "Earlier record",
    "Role in Bitcoin",
    "What the earlier record did not itself establish"
  ],
  "rows": [
    [
      "Digital signatures",
      "Diffie–Hellman, 1976",
      "Authorize spending conditions checked by nodes",
      "A shared ordering of conflicting spends"
    ],
    [
      "Hash-linked timestamps",
      "Haber–Stornetta, 1991",
      "Commit each block to its predecessor",
      "Open participation and chain selection by accumulated work"
    ],
    [
      "Computational proof",
      "Hashcash",
      "Make block production costly and verification inexpensive",
      "A ledger, monetary issuance, or transaction validation"
    ],
    [
      "Distributed digital money",
      "b-money, 1998",
      "Conceptual precedent for pseudonymous network money",
      "A deployed longest-proof-of-work-chain implementation"
    ],
    [
      "Bitcoin system",
      "Nakamoto paper and code, 2008–2009",
      "Combines validation, ordering, incentives, and issuance",
      "Broad adoption or proof of the creator’s private motives"
    ]
  ]
}