{
 "@context": "https://schema.org",
 "@type": "DefinedTerm",
 "@id": "https://wulfkaal.github.io/entities/double-spend",
 "identifier": "kaal:entity:double-spend",
 "name": "Double spend",
 "termCode": "double-spend",
 "inDefinedTermSet": {
  "@id": "https://wulfkaal.github.io/entities/index.json"
 },
 "author": {
  "@type": "Person",
  "name": "Wulf A. Kaal",
  "identifier": "https://orcid.org/0000-0003-0757-275X"
 },
 "dateModified": "2026-07-29",
 "canonicalForm": "https://wulfkaal.github.io/entities/double-spend.md",
 "sha256": "1fd1139e9fcfdc16ef6a3610ce3e511f5bca63e773f047ca0ea91e88cccc298c",
 "additionalProperty": [
  {
   "@type": "PropertyValue",
   "name": "status",
   "value": "derived"
  },
  {
   "@type": "PropertyValue",
   "name": "claim_count",
   "value": 3
  },
  {
   "@type": "PropertyValue",
   "name": "work_count",
   "value": 3
  },
  {
   "@type": "PropertyValue",
   "name": "year_span",
   "value": [
    "2019",
    "2021"
   ]
  },
  {
   "@type": "PropertyValue",
   "name": "non_current_claims",
   "value": 0
  }
 ],
 "subjectOf": [
  {
   "@type": "Claim",
   "@id": "https://wulfkaal.github.io/claims/3441904-024",
   "identifier": "kaal:claim:3441904-024",
   "text": "Hard forks can reintroduce the double spend problem, because wallets, merchants, and users running the previous code deem the new code invalid and cannot detect spending on it, so coins spent in a new block could be spent again on an old block.",
   "abstract": "Because wallets, merchants, and users running the previous code deem the new code invalid and thus cannot detect the spending on the new code, cryptocurrencies spent in a new block could be spent again on an old block.",
   "citation": "Wulf A. Kaal, Blockchain-Based Corporate Governance (2019). SSRN: https://ssrn.com/abstract=3441904",
   "datePublished": "2019",
   "claim_type": "mechanism",
   "confidence": "argued",
   "is_failure_mode": true,
   "scope_conditions": [
    "hard forks only, since old nodes read both block versions after a soft fork"
   ],
   "source_pdf_sha256": "e6b562527f7f19accaa35491db0a0db168b6a936755e1dca424e9f30bee7a815",
   "status": "current"
  },
  {
   "@type": "Claim",
   "@id": "https://wulfkaal.github.io/claims/3652481-018",
   "identifier": "kaal:claim:3652481-018",
   "text": "Bifurcation of nodes in a decentralized network through forking can cause significant economic loss, errors, confusion and bugs, including reemergence of the double spend problem that the pre fork network had already solved.",
   "abstract": "The bifurcation of nodes in a given decentralized network can lead to significant economic loss, errors, confusion, and bugs. For example, the bifurcation of network nodes can result in the reemergence of the double spend problem that the previous network had overcome.",
   "citation": "Wulf A. Kaal, Decentralized Autonomous Organizations – Internal Governance and External Legal Design (2020). SSRN: https://ssrn.com/abstract=3652481",
   "datePublished": "2020",
   "claim_type": "failure",
   "confidence": "argued",
   "is_failure_mode": true,
   "scope_conditions": [
    "a chain fork splits nodes across incompatible protocol versions"
   ],
   "source_pdf_sha256": "530b3a40c244aeca2eb4c53f4c9b4d6b2962bd6be9f92b4ebe17139c17f4c0e0",
   "status": "current"
  },
  {
   "@type": "Claim",
   "@id": "https://wulfkaal.github.io/claims/3808873-036",
   "identifier": "kaal:claim:3808873-036",
   "text": "Forking bifurcates network nodes and can reintroduce the double spend problem the network had already solved, because users running pre fork code treat post fork code as invalid and cannot detect spending on it, so coins spent in a post fork block can be spent again on a pre fork block.",
   "abstract": "For example, the bifurcation of network nodes can result in the reemergence of the double spend problem that the previous network had overcome. Users running the pre-fork code consider the post-fork code invalid, they cannot detect the spending on the post-fork code.",
   "citation": "Wulf A. Kaal, Decentralization Neutralizers (2021). SSRN: https://ssrn.com/abstract=3808873",
   "datePublished": "2021",
   "claim_type": "mechanism",
   "confidence": "argued",
   "is_failure_mode": true,
   "scope_conditions": [
    "hard forks producing parallel chains with incompatible protocol rules"
   ],
   "source_pdf_sha256": "f11493915e6b8c266d421510b5546816e33defb5650aac9d09b20d78549da727",
   "status": "current"
  }
 ],
 "description": "3 claims in the published works of Wulf A. Kaal carry the concept tag 'double-spend'. Derived node: a roster, not an adjudicated definition."
}