mrwulf
82ee511277
Port of the dalek Montgomery stack against THIS fork's own extraction (gen sections byte-identical, proofs recompiled from scratch here): - Proofs/ScalarMulSpec.lean - mul_internal: 9 exact schoolbook columns - Proofs/ScalarMontSpec.lean - part1/part2 exact-division rounds (LFACTOR*L0 = -1 mod 2^52), head/tail telescopes, mont_bound, tail walk - Proofs/ScalarReduceSpec.lean - montgomery_reduce main walk: scDenote r * 2^260 = Z in ZMod ell + 52-bit output bounds - Proofs/ScalarFullMulSpec.lean - mul = double Montgomery round through RR = R^2 mod ell; R cancelled as a unit; post: [mul a b] = [a]*[b] - Proofs/ScalarMain.lean - scalarImplementation aggregate (ScBnd interfaces; canonical inputs discharge the Montgomery bound) sub_val_spec/add_val_spec posts strengthened with result-limb bounds. check-scalar.sh: 9 proof files, 10 kernel audits, all exactly [propext, Classical.choice, Quot.sound]. Button pressed fresh: green.
3.4 KiB
risc0-ed25519-verified
Formal verification of the ed25519 implementation in risc0/curve25519-dalek (RISC Zero fork, v4.1.3), built as a coherent proof pyramid in Lean 4 via the Charon/Aeneas transpilation pipeline:
┌──────────────────────────────┐
│ Signature (EdDSA verify) │ accepted ⇒ [8][S]B = [8]R + [8][k]A
├──────────────────────────────┤
│ Scalar arithmetic mod ℓ │ Scalar52 ops correct mod ℓ
├──────────────────────────────┤
│ Group law (twisted Edwards) │ point ops = complete addition law
├──────────────────────────────┤
│ Field 𝔽_p, p = 2²⁵⁵ − 19 │ FieldElement51 ops correct mod p
└──────────────────────────────┘
Every layer states its theorems about the actual Aeneas-transpiled Rust
code (never about a hand-written re-model), and every claim in the status
table below is backed by a compiled proof plus an axiom audit of the named
certificate. Files that do not compile under verification/check.sh are not
in this repository.
Layer status
| Layer | Certificate | Status | Axioms of certificate |
|---|---|---|---|
| Field 𝔽_p | fieldImplementation |
✅ proven | [propext, Classical.choice, Quot.sound] |
| Group law (Edwards) | edwardsImplementation |
✅ proven | [propext, Classical.choice, Quot.sound] |
| Scalar mod ℓ | scalarImplementation (add ✅ sub ✅ mul ✅) |
✅ proven | [propext, Classical.choice, Quot.sound] |
| Signature (EdDSA) | verifyEquation (planned) |
⏳ planned | — |
Status legend: ✅ proven & axiom-audited · ⏳ in progress · ❌ not started.
This table is updated only when verification/check.sh passes for the layer.
Source
- Upstream: risc0/curve25519-dalek, commit
385adda - Pinned/patched source: saymrwulf/risc0-curve25519-dalek-source, commit
2643444 - Patches: minimal Aeneas-compatibility only (documented in the source repo)
- Scope caveat: this verifies the fork's pure-Rust
serial/u64path. The RISC Zero zkVM accelerator/syscall path is different code and is NOT covered by these proofs.
Toolchain (pinned)
| Component | Version |
|---|---|
| Aeneas | bf13c42e |
| Charon | 9dd7f23c |
| Lean | v4.30.0-rc2 |
| OCaml | 5.3.0 |
Reproducing
source ~/aeneas-toolchain/env.sh
cd verification
./extract.sh # Rust → LLBC → Lean (regenerates gen/)
./check.sh # compiles EVERY shipped file + axiom-audits EVERY certificate
The scalar layer has its own pair of buttons:
./extract-scalar.sh # regenerates gen/CurveScalar (Scalar52 limb arithmetic)
./check-scalar.sh # compiles the scalar gen + the proven scalar foundation
Trusted base
See TRUSTED-BASE.md for the complete list of assumptions (Lean kernel, mathlib, Charon/Aeneas semantics, external-function models, and — in the signature layer only — an opaque SHA-512 model).