{
  "type": "failure-mode",
  "name": "Proof malleability",
  "slug": "proof-malleability",
  "section": {
    "id": "audit",
    "number": "03",
    "title": "Auditing a ZK protocol",
    "url": "https://zkpick.com/audit/"
  },
  "url": "https://zkpick.com/audit/failure-modes/proof-malleability/",
  "markdown": "https://zkpick.com/md/audit/failure-modes/proof-malleability.md",
  "detail": "A valid proof can be transformed into a different valid proof for the same statement. Any system that treats a proof hash as a unique identifier — for deduplication, nonces or replay protection — breaks.",
  "mitigation": "Never treat proof bytes as a unique identifier. Derive uniqueness from constrained in-circuit values such as nullifiers, and canonicalise encodings on deserialisation.",
  "relatedOptions": [],
  "updated": "2026-09-12",
  "version": "1.3",
  "canonical": "https://zkpick.com/audit/failure-modes/proof-malleability/",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "authors": [
    "MarketComp"
  ]
}