saymrwulf
681ce95293
The solana fork's Scalar52 sub/add/conditional_add_l extract token-identical to upstream dalek (only the crate namespace differs: curve25519 vs curve25519_dalek), so ScalarSubSpec/ScalarAddSpec port with the namespace adjustment and verify against THIS fork's own gen (R2). ScalarLoop infrastructure included. check-scalar.sh at dalek parity: full manifest + 5/5 kernel axiom audit, green at 300s/4096MB. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
3.4 KiB
anza-ed25519-verified
Formal verification of the ed25519 implementation in anza-xyz/cryptography (Solana, solana-ed25519 crate), 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 | add_val_spec ✅ sub_val_spec ✅ (aggregate planned) |
🔨 add+sub done · mul next | ⟦add⟧/⟦sub⟧ = +/− in ZMod ℓ proven against THIS fork's extraction; Montgomery mul next |
| 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: anza-xyz/cryptography, commit
0a54cca - Pinned/patched source: saymrwulf/anza-cryptography-source, commit
77043ab - Patches: minimal Aeneas-compatibility only (documented in the source repo)
- Closest relative of the reference solution (same crate layout as solana-ed25519).
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).