{
  "$schema": "https://degreesofsatoshi.com/encyclopedia/schemas/article-v1.json",
  "schemaVersion": "1.0.0",
  "id": "bitcoin-multisig",
  "canonical": "https://degreesofsatoshi.com/encyclopedia/bitcoin-multisig/",
  "collection": "bitcoin",
  "title": "Bitcoin multisig: what a two-of-three wallet actually requires",
  "description": "Understand threshold signing, a two-of-three example, backup requirements and why three keys do not necessarily mean three independent people.",
  "aliases": [],
  "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": "A Bitcoin multisignature arrangement makes a spend require a specified threshold of signatures from an authorized key set. In a two-of-three example, two qualifying keys can authorize the spend. Its resilience depends on how keys, devices, recovery information and decision authority are actually separated.",
    "claimId": "bitcoin-multisig-quick-answer",
    "sourceIds": [
      "bitcoin-dev-transactions",
      "bip174"
    ]
  },
  "keyFacts": [
    {
      "label": "Threshold",
      "value": "Two-of-three requires two authorized signatures, not all three.",
      "sourceIds": [
        "bitcoin-dev-transactions"
      ],
      "id": "threshold",
      "claimId": "bitcoin-multisig-fact-threshold"
    },
    {
      "label": "Coordination",
      "value": "A PSBT can carry transaction details between participants before finalization.",
      "sourceIds": [
        "bip174"
      ],
      "id": "coordination",
      "claimId": "bitcoin-multisig-fact-coordination"
    },
    {
      "label": "Backup",
      "value": "The spending script and key information matter as well as private-key backups.",
      "sourceIds": [
        "bip380",
        "bip174"
      ],
      "id": "backup",
      "claimId": "bitcoin-multisig-fact-backup"
    }
  ],
  "prerequisites": [
    "private-keys-and-seed-phrases"
  ],
  "sections": [
    {
      "id": "threshold",
      "heading": "Follow a two-of-three decision",
      "sourceIds": [
        "bitcoin-dev-transactions"
      ],
      "paragraphs": [
        "Label three authorized keys A, B and C. A policy requiring two permits A+B, A+C or B+C. A alone is insufficient. If a party controls both A and B, the arrangement does not require agreement from two independent people.",
        "Multisignature describes an authorization rule, not a business structure. Device separation, custody agreements and organizational processes determine how that rule is used."
      ]
    },
    {
      "id": "sign",
      "heading": "What each signer should inspect",
      "sourceIds": [
        "bip174"
      ],
      "paragraphs": [
        "A partially signed transaction can carry the proposed inputs, outputs and signing information through several devices or participants. Each signer should verify the destination and fee rather than treat another participant’s signature as proof that the payment is appropriate.",
        "Once enough valid signatures are assembled, the transaction can be finalized for broadcast. Collecting a threshold does not itself establish that the network has accepted or confirmed it."
      ]
    },
    {
      "id": "backup",
      "heading": "Back up the policy as well as access",
      "sourceIds": [
        "bip380",
        "bip174"
      ],
      "paragraphs": [
        "Recovery can require the output descriptor or spending script and public-key information needed to reconstruct the wallet’s outputs. Keeping two secret keys while losing the policy metadata can make recovery harder.",
        "The ability to lose one of three keys is not permission to store the others together carelessly. Correlated loss or compromise can defeat the intended benefit."
      ]
    }
  ],
  "faq": [
    {
      "question": "Does multisig automatically prevent theft?",
      "answer": "No. An attacker who obtains enough signing authority, or signers who approve a harmful transaction, can still satisfy the policy. The threshold reduces particular single-key risks only when implemented and operated appropriately.",
      "sourceIds": [
        "bitcoin-dev-transactions",
        "bip174"
      ]
    }
  ],
  "claims": [
    {
      "id": "bitcoin-multisig-quick-answer",
      "articleSlug": "bitcoin-multisig",
      "statement": "A Bitcoin multisignature arrangement makes a spend require a specified threshold of signatures from an authorized key set. In a two-of-three example, two qualifying keys can authorize the spend. Its resilience depends on how keys, devices, recovery information and decision authority are actually separated.",
      "sourceIds": [
        "source-b282fdecc069b74d",
        "source-5790dff0294c8035"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-b282fdecc069b74d",
          "locator": "P2PKH Script Validation; Transaction Fees And Change"
        },
        {
          "sourceId": "source-5790dff0294c8035",
          "locator": "Roles; Creator; Updater; Signer; Finalizer"
        }
      ],
      "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": [
          "Read developer-guide Multisig/P2SH and BIP-174 signing/finalization roles; checked the three valid two-of-three combinations. Threshold signatures do not establish independent human decision makers.",
          "BIP-380 Motivation supports policy/derivation backup requirements. Possessing enough signing keys alone does not eliminate recovery-metadata or operational risks."
        ]
      }
    },
    {
      "id": "bitcoin-multisig-fact-threshold",
      "articleSlug": "bitcoin-multisig",
      "statement": "Threshold: Two-of-three requires two authorized signatures, not all three.",
      "sourceIds": [
        "source-b282fdecc069b74d"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-b282fdecc069b74d",
          "locator": "P2PKH Script Validation; Transaction Fees And Change"
        }
      ],
      "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": [
          "Read developer-guide Multisig/P2SH and BIP-174 signing/finalization roles; checked the three valid two-of-three combinations. Threshold signatures do not establish independent human decision makers.",
          "BIP-380 Motivation supports policy/derivation backup requirements. Possessing enough signing keys alone does not eliminate recovery-metadata or operational risks."
        ]
      }
    },
    {
      "id": "bitcoin-multisig-fact-coordination",
      "articleSlug": "bitcoin-multisig",
      "statement": "Coordination: A PSBT can carry transaction details between participants before finalization.",
      "sourceIds": [
        "source-5790dff0294c8035"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-5790dff0294c8035",
          "locator": "Roles; Creator; Updater; Signer; Finalizer"
        }
      ],
      "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": [
          "Read developer-guide Multisig/P2SH and BIP-174 signing/finalization roles; checked the three valid two-of-three combinations. Threshold signatures do not establish independent human decision makers.",
          "BIP-380 Motivation supports policy/derivation backup requirements. Possessing enough signing keys alone does not eliminate recovery-metadata or operational risks."
        ]
      }
    },
    {
      "id": "bitcoin-multisig-fact-backup",
      "articleSlug": "bitcoin-multisig",
      "statement": "Backup: The spending script and key information matter as well as private-key backups.",
      "sourceIds": [
        "source-36e62aca6baaa2f2",
        "source-5790dff0294c8035"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-36e62aca6baaa2f2",
          "locator": "Specification; Key expressions; Checksum"
        },
        {
          "sourceId": "source-5790dff0294c8035",
          "locator": "Roles; Creator; Updater; Signer; Finalizer"
        }
      ],
      "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": [
          "Read developer-guide Multisig/P2SH and BIP-174 signing/finalization roles; checked the three valid two-of-three combinations. Threshold signatures do not establish independent human decision makers.",
          "BIP-380 Motivation supports policy/derivation backup requirements. Possessing enough signing keys alone does not eliminate recovery-metadata or operational risks."
        ]
      }
    }
  ],
  "sources": [
    {
      "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": "bip174",
      "label": "Partially Signed Bitcoin Transaction Format",
      "publisher": "Bitcoin BIPs contributors",
      "url": "https://raw.githubusercontent.com/bitcoin/bips/927b6de9915c9262615a6399de51b200f81e5aa4/bip-0174.mediawiki",
      "locator": "Roles; Creator; Updater; Signer; Finalizer",
      "note": "Exchange of transaction and signing data across participants.",
      "version": "BIP-174; immutable revision pinned in source URL",
      "checkedAt": "2026-10-02T17:22:20.522Z",
      "contentSha256": "f2a8e1a9c9e31cc7f607b3c7e2419c63eeccc4bd5b725968cde54ab8cfa1d410",
      "recordId": "source-5790dff0294c8035"
    },
    {
      "id": "bip380",
      "label": "Output Script Descriptors General Operation",
      "publisher": "Bitcoin BIPs contributors",
      "url": "https://raw.githubusercontent.com/bitcoin/bips/927b6de9915c9262615a6399de51b200f81e5aa4/bip-0380.mediawiki",
      "locator": "Specification; Key expressions; Checksum",
      "note": "Descriptors describe output scripts, keys and derivation information.",
      "version": "BIP-380; immutable revision pinned in source URL",
      "checkedAt": "2026-10-02T17:22:20.620Z",
      "contentSha256": "34e6510bb2eba9445a68eacf3d24d5a4e5f24481477488d5552f674ac81dd5fe",
      "recordId": "source-36e62aca6baaa2f2"
    }
  ],
  "related": {
    "articles": [
      "partially-signed-bitcoin-transactions",
      "bitcoin-output-descriptors",
      "watch-only-wallets",
      "bitfinex-hack-2016"
    ],
    "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. “Bitcoin multisig: what a two-of-three wallet actually requires.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/bitcoin-multisig/"
}