{
  "type": "option",
  "name": "STIR and WHIR",
  "slug": "stir-whir",
  "section": {
    "id": "proof-systems",
    "number": "01",
    "title": "Choosing a proof system",
    "url": "https://zkpick.com/proof-systems/"
  },
  "url": "https://zkpick.com/proof-systems/stir-whir/",
  "markdown": "https://zkpick.com/md/proof-systems/stir-whir.md",
  "category": "Hash-based low-degree tests",
  "summary": "STIR and WHIR: Hash-based low-degree tests. Setup: None. Proof size: Markedly smaller than FRI at equal security. On-chain verification: Impractical directly. PQ: Plausibly. Recursion: Inherits FRI approaches. Maturity: Research maturing into implementation. Prover cost profile: Comparable to FRI; the WHIR prover is somewhat heavier. Peak prover memory: As FRI. Off-chain verifier: Sub-millisecond for WHIR in the authors' reported settings. Implementations and maintainers: Reference implementations by the authors; integrations into production hash-based stacks under way. Where it is measured: Authors' comparisons only; measure on your own parameters. Choose it when: Replacing FRI where hash-based proof size or verifier latency is the binding constraint, for teams who will follow the literature.",
  "description": "Two successors to FRI from the same research lineage. STIR reduces query complexity by recursively improving the rate of the tested code; WHIR builds on constrained Reed–Solomon codes to give very fast verification, and doubles as a polynomial commitment.",
  "notes": [],
  "sections": [],
  "strengths": [
    "Concretely smaller proofs than FRI at equal security — roughly half, in the authors' reported comparisons",
    "WHIR verification is reported in hundreds of microseconds where prior hash-based verifiers took milliseconds",
    "Public reference implementations exist and integration into production stacks is under way"
  ],
  "tradeoffs": [
    "Newer analyses and fewer independent implementations than FRI",
    "The most aggressive parameterisation relied on an up-to-capacity conjecture disproved for large fields in late 2025; Johnson-bound parameters are unaffected but the optimistic discount is not available as originally stated",
    "Requires a team able to track fresh cryptanalysis"
  ],
  "bestFit": "Replacing FRI where hash-based proof size or verifier latency is the binding constraint, for teams who will follow the literature.",
  "maintainers": "Arnon, Chiesa, Fenzi and Yogev (2024). Reference implementations by the authors; integrations at several hash-based zkVM teams",
  "maturity": "Research maturing into implementation",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "source": "https://eprint.iacr.org/2024/1586",
  "facts": [
    {
      "table": "Proof system selection matrix",
      "url": "https://zkpick.com/proof-systems/#proof-systems-matrix-stir-whir",
      "name": "STIR / WHIR",
      "setup": "None",
      "size": "Markedly smaller than FRI at equal security",
      "verify": "Impractical directly",
      "pq": "Plausibly",
      "recursion": "Inherits FRI approaches",
      "maturity": "Research maturing into implementation"
    },
    {
      "table": "Prover profile, implementations and benchmarks",
      "url": "https://zkpick.com/proof-systems/#proof-systems-matrix-2-stir-whir",
      "name": "STIR / WHIR",
      "prover": "Comparable to FRI; the WHIR prover is somewhat heavier",
      "memory": "As FRI",
      "offchain": "Sub-millisecond for WHIR in the authors' reported settings",
      "impls": "Reference implementations by the authors; integrations into production hash-based stacks under way",
      "bench": "Authors' comparisons only; measure on your own parameters"
    }
  ],
  "relatedFailureModes": [],
  "sources": [
    {
      "title": "STIR — Reed–Solomon proximity testing with fewer queries",
      "url": "https://eprint.iacr.org/2024/390",
      "kind": "paper"
    },
    {
      "title": "WHIR — Reed–Solomon proximity testing with super-fast verification",
      "url": "https://eprint.iacr.org/2024/1586",
      "kind": "paper"
    }
  ],
  "updated": "2026-09-12",
  "version": "1.3",
  "canonical": "https://zkpick.com/proof-systems/stir-whir/",
  "authors": [
    "MarketComp"
  ]
}