{
  "slug": "isabelle",
  "name": "Isabelle/HOL",
  "tagline": "Proof assistant used by Apple to verify corecrypto ML-KEM and ML-DSA",
  "maintainer": "TU München and University of Cambridge",
  "url": "https://isabelle.in.tum.de",
  "category": "provers",
  "targets": [
    "C and ARM64 via AutoCorres2",
    "Apple corecrypto"
  ],
  "approach": "Higher-order logic with strong automation; refinement via AutoCorres2",
  "license": "Open source (BSD)",
  "status": "Active",
  "summary": "Isabelle/HOL is the prover Apple used with AutoCorres2, SAW and Cryptol to verify the ML-KEM and ML-DSA implementations in corecrypto (published 2026). It offers strong automation and a refinement methodology for C.",
  "details": [
    "Apple's corecrypto work is the largest public post-quantum verification effort by a device vendor and a reference for refinement-based methodology."
  ],
  "strengths": [
    "Powerful automation (sledgehammer).",
    "AutoCorres2 for C refinement.",
    "Industrial precedent (seL4, corecrypto)."
  ],
  "limits": [
    "Little ZK ecosystem presence.",
    "Different culture and libraries from Lean/Rocq.",
    "Refinement setups are heavyweight."
  ],
  "fit": [
    "Choose Isabelle for C or ARM64 refinement proofs in the seL4 tradition."
  ],
  "references": [
    [
      "Apple corecrypto",
      "https://github.com/apple/corecrypto"
    ],
    [
      "Isabelle",
      "https://isabelle.in.tum.de"
    ]
  ],
  "category_name": "Proof assistants and general verifiers",
  "page": "https://sorryfree.com/frameworks/isabelle/",
  "updated": "2026-09-13"
}