Files
zooqueenandHanzo Dev ac9676a47a proofs: drive formal/lean library to 0 errors
The formal/lean library (53 files — a separate formalization from lean/) had
~110 type-check errors across 38 files and had never had its Mathlib oleans
built. It now verifies at 0 errors under the project's strict setting:
`lake env lean -D autoImplicit=false`, all 53 files.

Fixed the same families as the sibling lean/ tree (the content is diverged, so
each was repaired directly):
- Crypto (BLS/FROST/Corona/Hybrid/threshold/FHE/Verkle): omega needs in-scope
  structure invariants; Nat-division bounds; noncomputable over opaque verifiers;
  Fin n index → Nat; deriving Inhabited.
- DeFi (AMM/staking/fees/flashloan/HFT/router): constant-product invariant and
  fee bounds via Nat.div_mul_le_self / Nat.div_le_of_le_mul; dead tactics.
- Protocol/Consensus/Warp/Bridge: BFT quorum theorems tightened to n=3f+1;
  pipe-projection parse fixes; split-after-simp; dead tactics; built the
  Consensus/Safety + ThresholdProof dependency oleans from clean source.
- Network/Compute/Trust/Build: record-projection opacity (unfold+split),
  foldl-min monotonicity, BEq parse parens.
- autoImplicit=false: declared previously auto-bound variables (explicit binders
  / variable blocks); the lakefile sets autoImplicit:=false.

Integrity: no sorry/admit/native_decide; no proof-by-assumption axiom cheats.
Statement changes only tightened false/trivial draft theorems to true
invariants. Remaining axioms are trusted-base only (opaque crypto primitives,
protocol modeling / honesty-static, build determinism).

Co-authored-by: Hanzo Dev <[email protected]>
2026-06-02 09:31:40 -07:00

106 lines
3.8 KiB
Lean4

/-
Post-Quantum Hybrid Signature Correctness
Models the hybrid signature scheme combining:
- Ed25519 (classical, 32-byte keys)
- ML-DSA-65 (FIPS 204, lattice-based, 1952-byte keys)
- SLH-DSA-128s (FIPS 205, hash-based, 32-byte keys)
The hybrid construction requires ALL three to verify.
An attacker must break all three to forge — defense in depth.
Maps to:
- luxfi/crypto: hybrid package
- lux/node: validator identity keys
Properties:
- Defense in depth: full verify ⟹ all three verify
- Classical fallback: fast mode uses ed25519 + ML-DSA only
- Hash-based backup: SLH-DSA protects if lattices fall
-/
import Mathlib.Data.Nat.Defs
import Mathlib.Tactic
namespace Crypto.Hybrid
/-- Abstract signature verification for each scheme -/
axiom ed25519_verify : Nat → Nat → Nat → Bool
axiom mldsa_verify : Nat → Nat → Nat → Bool
axiom slhdsa_verify : Nat → Nat → Nat → Bool
/-- Hybrid public key: classical + lattice + hash-based -/
structure HybridPK where
ed25519 : Nat
mldsa : Nat
slhdsa : Nat
/-- Hybrid signature: one from each scheme -/
structure HybridSig where
ed25519 : Nat
mldsa : Nat
slhdsa : Nat
/-- Verification modes -/
inductive VerifyMode where
| fast -- ed25519 + ML-DSA (performance)
| full -- all three (maximum security)
| classical -- ed25519 only (fallback)
/-- Fast verification: ed25519 ∧ ML-DSA.
`noncomputable` because the per-scheme verifiers are abstract axioms. -/
noncomputable def verify_fast (pk : HybridPK) (msg : Nat) (sig : HybridSig) : Bool :=
ed25519_verify pk.ed25519 msg sig.ed25519 &&
mldsa_verify pk.mldsa msg sig.mldsa
/-- Full verification: ed25519 ∧ ML-DSA ∧ SLH-DSA.
`noncomputable` because the per-scheme verifiers are abstract axioms. -/
noncomputable def verify_full (pk : HybridPK) (msg : Nat) (sig : HybridSig) : Bool :=
ed25519_verify pk.ed25519 msg sig.ed25519 &&
mldsa_verify pk.mldsa msg sig.mldsa &&
slhdsa_verify pk.slhdsa msg sig.slhdsa
/-- Mode-selected verification.
`noncomputable` because the per-scheme verifiers are abstract axioms. -/
noncomputable def verify (pk : HybridPK) (msg : Nat) (sig : HybridSig) (mode : VerifyMode) : Bool :=
match mode with
| .fast => verify_fast pk msg sig
| .full => verify_full pk msg sig
| .classical => ed25519_verify pk.ed25519 msg sig.ed25519
/-- DEFENSE IN DEPTH: Full verification requires all three schemes.
An attacker must break ed25519 AND ML-DSA AND SLH-DSA. -/
theorem full_requires_all_three (pk : HybridPK) (msg : Nat) (sig : HybridSig)
(h : verify_full pk msg sig = true) :
ed25519_verify pk.ed25519 msg sig.ed25519 = true ∧
mldsa_verify pk.mldsa msg sig.mldsa = true ∧
slhdsa_verify pk.slhdsa msg sig.slhdsa = true := by
simp only [verify_full, Bool.and_eq_true] at h
obtain ⟨h12, h3⟩ := h
obtain ⟨h1, h2⟩ := h12
exact ⟨h1, h2, h3⟩
/-- Fast mode requires both ed25519 and ML-DSA -/
theorem fast_requires_both (pk : HybridPK) (msg : Nat) (sig : HybridSig)
(h : verify_fast pk msg sig = true) :
ed25519_verify pk.ed25519 msg sig.ed25519 = true ∧
mldsa_verify pk.mldsa msg sig.mldsa = true := by
simp only [verify_fast, Bool.and_eq_true] at h
exact h
/-- Full implies fast: if all three verify, the fast pair certainly does -/
theorem full_implies_fast (pk : HybridPK) (msg : Nat) (sig : HybridSig)
(h : verify_full pk msg sig = true) :
verify_fast pk msg sig = true := by
have ⟨h1, h2, _⟩ := full_requires_all_three pk msg sig h
simp [verify_fast, h1, h2]
/-- Full implies classical: if all three verify, ed25519 certainly does -/
theorem full_implies_classical (pk : HybridPK) (msg : Nat) (sig : HybridSig)
(h : verify_full pk msg sig = true) :
verify pk msg sig .classical = true := by
have ⟨h1, _, _⟩ := full_requires_all_three pk msg sig h
simp [verify, h1]
end Crypto.Hybrid