{
 "@context": "https://schema.org",
 "@type": "DefinedTerm",
 "@id": "https://wulfkaal.github.io/entities/fork-choice",
 "identifier": "kaal:entity:fork-choice",
 "name": "Fork choice",
 "termCode": "fork-choice",
 "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/fork-choice.md",
 "sha256": "064203c28ccff3615587b87ff1bc2be8f1f7dbdbbfa51e3557a05b29b23239a8",
 "additionalProperty": [
  {
   "@type": "PropertyValue",
   "name": "status",
   "value": "derived"
  },
  {
   "@type": "PropertyValue",
   "name": "claim_count",
   "value": 3
  },
  {
   "@type": "PropertyValue",
   "name": "work_count",
   "value": 1
  },
  {
   "@type": "PropertyValue",
   "name": "year_span",
   "value": [
    "2018",
    "2018"
   ]
  },
  {
   "@type": "PropertyValue",
   "name": "non_current_claims",
   "value": 0
  }
 ],
 "subjectOf": [
  {
   "@type": "Claim",
   "@id": "https://wulfkaal.github.io/claims/3125827-015",
   "identifier": "kaal:claim:3125827-015",
   "text": "The long range attack is a fundamental problem every proof of stake protocol must address: because no energetic outlay is required to build blocks, a malicious producer can fabricate a long chain forked from an earlier valid block, and a newly joining node lacking proof of work hashes cannot objectively tell which chain is genuine.",
   "abstract": "The long-range attack is a fundamental problem PoS protocols must address, where a malicious producer may create a long list of blocks forked from an earlier valid block, because there is no PoW energetic outlay required to prevent this16.",
   "citation": "Craig Calcaterra, Wulf A. Kaal, Secure Proof of Stake Protocol (2018). SSRN: https://ssrn.com/abstract=3125827",
   "datePublished": "2018",
   "claim_type": "failure",
   "confidence": "argued",
   "is_failure_mode": true,
   "scope_conditions": [
    "new nodes joining without a trusted checkpoint",
    "PoS chains with no energy cost to block creation"
   ],
   "source_pdf_sha256": "598d9bd95e4af7a0a35328677c6bfc069f69f2e32c30c720b3a0be98a23a40cb",
   "status": "current"
  },
  {
   "@type": "Claim",
   "@id": "https://wulfkaal.github.io/claims/3125827-016",
   "identifier": "kaal:claim:3125827-016",
   "text": "SPoS prevents the long range attack without token locking, because a false chain cannot be manufactured with more total validation than the real chain: votes are transactions moving validators' sem tokens under their public keys, so upvotes cannot be forged from existing tokens.",
   "abstract": "SPoS naturally prevents this attack without such locking, since a false chain cannot be manufactured with more total validation than the real chain.",
   "citation": "Craig Calcaterra, Wulf A. Kaal, Secure Proof of Stake Protocol (2018). SSRN: https://ssrn.com/abstract=3125827",
   "datePublished": "2018",
   "claim_type": "mechanism",
   "confidence": "argued",
   "is_failure_mode": false,
   "scope_conditions": [
    "votes recorded as sem token transactions signed by validator public keys"
   ],
   "source_pdf_sha256": "598d9bd95e4af7a0a35328677c6bfc069f69f2e32c30c720b3a0be98a23a40cb",
   "status": "current"
  },
  {
   "@type": "Claim",
   "@id": "https://wulfkaal.github.io/claims/3125827-029",
   "identifier": "kaal:claim:3125827-029",
   "text": "If a Byzantine producer equivocates during a network partition and wins validation pools in separate subnets, the fork is not permanent: once connectivity is restored the next honest producer points to a previous block, and with 51% honest producers the Byzantine fork is eventually orphaned because honest producers outproduce it.",
   "abstract": "The next honest producer would point to a previous block and all Byzantine forks would be invalidated. If there are 51% honest producers the Byzantine fork would eventually be orphaned, since honest producers will outproduce the Byzantine producers",
   "citation": "Craig Calcaterra, Wulf A. Kaal, Secure Proof of Stake Protocol (2018). SSRN: https://ssrn.com/abstract=3125827",
   "datePublished": "2018",
   "claim_type": "mechanism",
   "confidence": "argued",
   "is_failure_mode": false,
   "scope_conditions": [
    "at least 51% honest producers",
    "network connectivity is eventually restored"
   ],
   "source_pdf_sha256": "598d9bd95e4af7a0a35328677c6bfc069f69f2e32c30c720b3a0be98a23a40cb",
   "status": "current"
  }
 ],
 "description": "3 claims in the published works of Wulf A. Kaal carry the concept tag 'fork-choice'. Derived node: a roster, not an adjudicated definition."
}