{
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  "id": "simplified-payment-verification",
  "canonical": "https://degreesofsatoshi.com/encyclopedia/simplified-payment-verification/",
  "collection": "bitcoin",
  "title": "SPV wallets: what a lightweight Bitcoin check can establish",
  "description": "Learn what Bitcoin SPV checks using headers and Merkle branches, and how its assurances differ from full transaction validation.",
  "aliases": [
    "SPV"
  ],
  "dates": {
    "published": "2026-10-02",
    "modified": "2026-10-02",
    "verified": "2026-10-02T18:15:23.891Z",
    "dataAsOf": "2026-10-02"
  },
  "authorship": {
    "publisher": "Degrees of Satoshi editorial project",
    "process": "AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied."
  },
  "quickAnswer": {
    "text": "Simplified Payment Verification, described in section 8 of the Bitcoin white paper, uses block headers and a Merkle branch to check that a payment appears in a chain with accumulated proof of work. It avoids downloading every full block but does not independently validate every transaction rule as a full node does.",
    "claimId": "simplified-payment-verification-quick-answer",
    "sourceIds": [
      "bitcoin-whitepaper",
      "bitcoin-dev-blockchain"
    ]
  },
  "keyFacts": [
    {
      "label": "Data",
      "value": "The design uses headers plus transaction inclusion information.",
      "sourceIds": [
        "bitcoin-whitepaper"
      ],
      "id": "data",
      "claimId": "simplified-payment-verification-fact-data"
    },
    {
      "label": "Assumption",
      "value": "Its assurances depend on the chain view and honest-network assumptions described in the paper.",
      "sourceIds": [
        "bitcoin-whitepaper"
      ],
      "id": "assumption",
      "claimId": "simplified-payment-verification-fact-assumption"
    },
    {
      "label": "Distinction",
      "value": "A wallet that trusts an explorer response is not necessarily performing SPV.",
      "sourceIds": [
        "bitcoin-whitepaper"
      ],
      "id": "distinction",
      "claimId": "simplified-payment-verification-fact-distinction"
    }
  ],
  "prerequisites": [
    "bitcoin-merkle-proofs"
  ],
  "sections": [
    {
      "id": "checks",
      "heading": "What the small client can establish",
      "sourceIds": [
        "bitcoin-whitepaper"
      ],
      "paragraphs": [
        "A header commits to a transaction tree and links to the preceding header. With an inclusion branch, a client can check the payment against that commitment and observe work accumulated after the block.",
        "The white paper explicitly distinguishes this from checking the transaction for oneself. A concise proof is useful, but its scope should be described accurately."
      ]
    },
    {
      "id": "full-node",
      "heading": "Why a full node has a different role",
      "sourceIds": [
        "bitcoin-dev-blockchain",
        "bitcoin-dev-transactions",
        "core-pruning-release"
      ],
      "paragraphs": [
        "A fully validating node checks transactions and blocks against consensus rules, including whether inputs exist and their spending conditions are met. Merely following the most-work headers omits those full-data checks.",
        "A pruned full node can still perform validation while discarding old block bodies afterward. Low retained disk usage and SPV are therefore not synonyms."
      ]
    },
    {
      "id": "wallet-label",
      "heading": "Ask what the wallet actually verifies",
      "sourceIds": [
        "bitcoin-whitepaper"
      ],
      "paragraphs": [
        "“Light wallet” covers several designs. Some consult one service, some download headers, and some use other filtering or proof arrangements. The label alone does not identify the verification model.",
        "Identify who supplies data, what the client verifies locally and how it handles conflicting chain views. These details determine what a displayed confirmation count means."
      ]
    }
  ],
  "faq": [
    {
      "question": "Is a pruned Bitcoin node an SPV client?",
      "answer": "No. Pruning concerns which old files a node retains after validation. SPV changes which information the client downloads and which rules it can independently check.",
      "sourceIds": [
        "core-pruning-release",
        "bitcoin-whitepaper"
      ]
    }
  ],
  "claims": [
    {
      "id": "simplified-payment-verification-quick-answer",
      "articleSlug": "simplified-payment-verification",
      "statement": "Simplified Payment Verification, described in section 8 of the Bitcoin white paper, uses block headers and a Merkle branch to check that a payment appears in a chain with accumulated proof of work. It avoids downloading every full block but does not independently validate every transaction rule as a full node does.",
      "sourceIds": [
        "source-0e46aca4dbc5a030",
        "source-190b9fe0eec933dc"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-0e46aca4dbc5a030",
          "locator": "Sections 4–5 and 7–11"
        },
        {
          "sourceId": "source-190b9fe0eec933dc",
          "locator": "Proof Of Work; Block Height And Forking; Transaction Data"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T18:15:23.891Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Independently reopened the original PDF and read section 8, including honest-network assumptions and inability to check the transaction fully. Headers plus an inclusion branch differ from merely trusting an explorer.",
          "Added Core pruning-release reference to the full-node comparison. Pruning after validation and SPV verification are not equated."
        ]
      }
    },
    {
      "id": "simplified-payment-verification-fact-data",
      "articleSlug": "simplified-payment-verification",
      "statement": "Data: The design uses headers plus transaction inclusion information.",
      "sourceIds": [
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      ],
      "sourceLocators": [
        {
          "sourceId": "source-0e46aca4dbc5a030",
          "locator": "Sections 4–5 and 7–11"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
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        "method": "independent automated source review",
        "checkedAt": "2026-10-02T18:15:23.891Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Independently reopened the original PDF and read section 8, including honest-network assumptions and inability to check the transaction fully. Headers plus an inclusion branch differ from merely trusting an explorer.",
          "Added Core pruning-release reference to the full-node comparison. Pruning after validation and SPV verification are not equated."
        ]
      }
    },
    {
      "id": "simplified-payment-verification-fact-assumption",
      "articleSlug": "simplified-payment-verification",
      "statement": "Assumption: Its assurances depend on the chain view and honest-network assumptions described in the paper.",
      "sourceIds": [
        "source-0e46aca4dbc5a030"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-0e46aca4dbc5a030",
          "locator": "Sections 4–5 and 7–11"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T18:15:23.891Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Independently reopened the original PDF and read section 8, including honest-network assumptions and inability to check the transaction fully. Headers plus an inclusion branch differ from merely trusting an explorer.",
          "Added Core pruning-release reference to the full-node comparison. Pruning after validation and SPV verification are not equated."
        ]
      }
    },
    {
      "id": "simplified-payment-verification-fact-distinction",
      "articleSlug": "simplified-payment-verification",
      "statement": "Distinction: A wallet that trusts an explorer response is not necessarily performing SPV.",
      "sourceIds": [
        "source-0e46aca4dbc5a030"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-0e46aca4dbc5a030",
          "locator": "Sections 4–5 and 7–11"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
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      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
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        "checkedAt": "2026-10-02T18:15:23.891Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Independently reopened the original PDF and read section 8, including honest-network assumptions and inability to check the transaction fully. Headers plus an inclusion branch differ from merely trusting an explorer.",
          "Added Core pruning-release reference to the full-node comparison. Pruning after validation and SPV verification are not equated."
        ]
      }
    }
  ],
  "sources": [
    {
      "id": "bitcoin-whitepaper",
      "label": "Bitcoin: A Peer-to-Peer Electronic Cash System",
      "publisher": "Satoshi Nakamoto",
      "url": "https://bitcoin.org/bitcoin.pdf",
      "locator": "Sections 4–5 and 7–11",
      "note": "Most-work chain selection, Merkle inclusion, SPV limits and transaction change.",
      "version": "2008 paper",
      "checkedAt": "2026-10-02T17:03:41.335Z",
      "contentSha256": "b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553",
      "recordId": "source-0e46aca4dbc5a030"
    },
    {
      "id": "bitcoin-dev-blockchain",
      "label": "Bitcoin Developer Guide: Block Chain",
      "publisher": "Bitcoin developer documentation contributors",
      "url": "https://developer.bitcoin.org/devguide/block_chain.html",
      "locator": "Proof Of Work; Block Height And Forking; Transaction Data",
      "note": "Block headers, transaction Merkle trees and competing valid branches.",
      "version": null,
      "checkedAt": "2026-10-02T17:03:41.181Z",
      "contentSha256": "0102eb1bda0d084051a86735e4b293dadc5a93b2bee93ad71c62cfeb855f1583",
      "recordId": "source-190b9fe0eec933dc"
    },
    {
      "id": "bitcoin-dev-transactions",
      "label": "Bitcoin Developer Guide: Transactions",
      "publisher": "Bitcoin developer documentation contributors",
      "url": "https://developer.bitcoin.org/devguide/transactions.html",
      "locator": "P2PKH Script Validation; Transaction Fees And Change",
      "note": "UTXO inputs, transaction outputs, change and the difference paid as a fee.",
      "version": null,
      "checkedAt": "2026-10-02T17:03:41.190Z",
      "contentSha256": "449ae88ea59f9b198c398d3f5f56f83a92cd6be1638fa6681a1fdeea164892c0",
      "recordId": "source-b282fdecc069b74d"
    },
    {
      "id": "core-pruning-release",
      "label": "Bitcoin Core 0.11.0 release notes",
      "publisher": "Bitcoin Core",
      "url": "https://bitcoincore.org/en/releases/0.11.0/",
      "locator": "Block file pruning",
      "note": "Pruning removes old block files after validation while retaining chainstate.",
      "version": "Bitcoin Core 0.11.0 historical introduction",
      "checkedAt": "2026-10-02T17:03:41.974Z",
      "contentSha256": "bfba2b0e8a351ef0032fb0f2e8f6892c31214792ef249376feefa524943fd9f1",
      "recordId": "source-997df60df1815097"
    }
  ],
  "related": {
    "articles": [
      "pruned-bitcoin-nodes",
      "bitcoin-merkle-proofs",
      "bitcoin-nodes-explained"
    ],
    "dossiers": [],
    "wallets": []
  },
  "revisionHistory": [
    {
      "date": "2026-10-02",
      "kind": "published",
      "summary": "Initial Bitcoin encyclopedia entry at this permanent URL."
    },
    {
      "date": "2026-10-02",
      "kind": "publishing-format",
      "summary": "Added reusable claims, explicit source locators, and matching Markdown and JSON. This publishing change does not itself establish factual verification."
    }
  ],
  "citation": "Degrees of Satoshi editorial project. “SPV wallets: what a lightweight Bitcoin check can establish.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/simplified-payment-verification/"
}