Files
zeekay c86eec94cb merge: absorb /Users/z/work/zoo/formal into proofs (de-duplicate)
Local zoo/formal was a stale parallel checkout that pointed at
zoo-labs/formal (non-existent); the canonical remote is
zooai/proofs. This commit absorbs the unique formal-verification
work from the old checkout into proofs:

- formal/    (Lean 4 proofs source — duplicate of top-level lean/
              but kept as separate "formal/" entry for the
              legacy import path)
- halmos/    (Solidity symbolic-exec contracts: AMMInvariant,
              LiquidSolvency, MarketsSolvency, FHEInvariant)
- property/  (Go property-test suite for FHE noise)
- tamarin/   (Tamarin protocol-verification source)
- tla/       (TLA+ system-spec source)
- lean/Contract/ZKSignature.lean  (unique, not in proofs/lean)
- lean/Crypto/ZKSignature.lean    (unique, not in proofs/lean)
- FORMAL_VERIFICATION.md (preserved from the old README)
- LLM-formal.md          (preserved from the old LLM.md)

The duplicate folder /Users/z/work/zoo/formal is now deleted on
disk. One canonical checkout: /Users/z/work/zoo/proofs tracking
github:zooai/proofs.
2026-05-12 21:13:00 -07:00

81 lines
2.6 KiB
Lean4

/-
ML-DSA (FIPS 204) Signature Correctness
Models the ML-DSA precompile (src/precompiles/mldsa/).
ML-DSA is the NIST post-quantum digital signature standard,
based on the Fiat-Shamir with Aborts paradigm over module lattices.
Maps to:
- src/precompiles/mldsa/: Go implementation
- luxfi/crypto: ML-DSA package
Properties:
- Correctness: sign then verify always succeeds
- EUF-CMA: existential unforgeability under chosen message attack
- Signature size: 3309 bytes for ML-DSA-65 (security level 3)
-/
import Mathlib.Data.Nat.Defs
import Mathlib.Tactic
namespace Crypto.MLDSA
/-- ML-DSA security levels -/
inductive SecurityLevel where
| level2 : SecurityLevel -- ML-DSA-44 (128-bit)
| level3 : SecurityLevel -- ML-DSA-65 (192-bit)
| level5 : SecurityLevel -- ML-DSA-87 (256-bit)
/-- Signature sizes by security level -/
def sigSize (l : SecurityLevel) : Nat :=
match l with
| .level2 => 2420
| .level3 => 3309
| .level5 => 4627
/-- Public key sizes -/
def pkSize (l : SecurityLevel) : Nat :=
match l with
| .level2 => 1312
| .level3 => 1952
| .level5 => 2592
/-- Abstract sign and verify functions for ML-DSA -/
axiom mldsa_sign : SecurityLevel → Nat → Nat → Nat
axiom mldsa_verify : SecurityLevel → Nat → Nat → Nat → Bool
axiom mldsa_correctness :
∀ (l : SecurityLevel) (sk pk msg : Nat),
-- For a valid key pair (sk, pk), sign then verify always succeeds
mldsa_verify l pk msg (mldsa_sign l sk msg) = true
/-- EUF-CMA security under Module-LWE assumption -/
axiom mldsa_euf_cma :
∀ (l : SecurityLevel) (pk msg : Nat) (forgery : Nat),
-- No PPT/quantum adversary can forge a signature on a new message
-- even after seeing signatures on chosen messages (Module-LWE hardness)
mldsa_verify l pk msg forgery = true →
∃ (sk : Nat), forgery = mldsa_sign l sk msg
/-- Signature size is bounded -/
theorem sig_size_bounded (l : SecurityLevel) :
sigSize l ≤ 5000 := by
cases l <;> simp [sigSize]
/-- ML-DSA-65 is the default for Lux (NIST Level 3, 192-bit security) -/
theorem default_level_3 : sigSize .level3 = 3309 := rfl
/-- Public key size at level 3 -/
theorem pk_size_level3 : pkSize .level3 = 1952 := rfl
/-- Security levels are ordered -/
theorem level2_lt_level3 : sigSize .level2 < sigSize .level3 := by simp [sigSize]
theorem level3_lt_level5 : sigSize .level3 < sigSize .level5 := by simp [sigSize]
/-- All signature sizes fit in a network packet (< 5KB) -/
theorem all_sigs_bounded : ∀ l : SecurityLevel, sigSize l < 5000 := by
intro l; cases l <;> simp [sigSize]
end Crypto.MLDSA