Research-Stack/0-Core-Formalism/lean/external/OTOM/StructuralAttestation.lean

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/-
StructuralAttestation.lean - Mechanical Merkle Trees & Structural Cryptography
Formalizes the bridge between physical structural integrity and computational validity.
Based on Tech Note: Mechanical Merkle Tree (Proof-of-State).
-/
import Semantics.FixedPoint
import Semantics.Bind
namespace Semantics.StructuralAttestation
open Q16_16
/--
A 6-axis stress vector representing strain gauge data.
(σx, σy, σz, τxy, τyz, τzx)
-/
structure StressVector where
sigmaX : Q16_16
sigmaY : Q16_16
sigmaZ : Q16_16
tauXY : Q16_16
tauYZ : Q16_16
tauZX : Q16_16
deriving Repr, DecidableEq
/--
A Mechanical Hash (structural signature).
In hardware, this is derived via Blake3(vector).
In the formal core, we use a sum-reduction for reachability proofs.
-/
def mechanicalHash (v : StressVector) : UInt32 :=
v.sigmaX.val ^^^ v.sigmaY.val ^^^ v.sigmaZ.val ^^^
v.tauXY.val ^^^ v.tauYZ.val ^^^ v.tauZX.val
/--
A node in the Mechanical Merkle Tree.
Each node has a local stress state and a combined hash of its children.
-/
inductive MechanicalMerkleTree
| leaf (id : Nat) (stress : StressVector)
| node (hash : UInt32) (left right : MechanicalMerkleTree)
deriving Repr
/-- Compute the root hash of a Mechanical Merkle Tree. -/
def rootHash : MechanicalMerkleTree → UInt32
| .leaf _ stress => mechanicalHash stress
| .node h _ _ => h
/--
Build a node from two subtrees.
Root hash is the XOR-sum of children's hashes (simplified hardware-native hash).
-/
def mkNode (l r : MechanicalMerkleTree) : MechanicalMerkleTree :=
.node (rootHash l ^^^ rootHash r) l r
/--
The Ideal Manifold: The target structural state (zero stress baseline).
-/
def idealManifoldHash : UInt32 := 0
/--
Admissibility: A structural state is admissible if its root hash
is within the allowed stability epsilon of the ideal manifold.
-/
def isStructurallyAdmissible (tree : MechanicalMerkleTree) (epsilon : UInt32) : Bool :=
let h := rootHash tree
h <= epsilon -- Simplified stability check
/--
The Security Veto: Computational results are only valid
if the physical structure is intact.
-/
def securityVeto (tree : MechanicalMerkleTree) (epsilon : UInt32) : Bool :=
not (isStructurallyAdmissible tree epsilon)
/--
Mechanical Bind: Chains structural integrity to semantic validity.
-/
def structuralBind (tree : MechanicalMerkleTree) (epsilon : UInt32) (g : Metric) : Bind MechanicalMerkleTree String :=
controlBind tree "structural_attestation" g
(fun t _ _ => if isStructurallyAdmissible t epsilon then zero.val else one.val)
(fun t => if isStructurallyAdmissible t epsilon then "structural_attestation" else "VETO:PHYSICAL_INTEGRITY_COMPROMISED")
(fun t => t)
-- #eval Witness:
-- Healthy state (all zeros) vs Damaged state (high stress)
def healthyLeaf : MechanicalMerkleTree := .leaf 0 { sigmaX := zero, sigmaY := zero, sigmaZ := zero, tauXY := zero, tauYZ := zero, tauZX := zero }
def healthyTree : MechanicalMerkleTree := mkNode healthyLeaf healthyLeaf
def damagedLeaf : MechanicalMerkleTree := .leaf 1 { sigmaX := ⟨0xFFFFFFFF⟩, sigmaY := zero, sigmaZ := zero, tauXY := zero, tauYZ := zero, tauZX := zero }
def damagedTree : MechanicalMerkleTree := mkNode healthyLeaf damagedLeaf
#eval rootHash healthyTree
#eval rootHash damagedTree
#eval isStructurallyAdmissible damagedTree 1000
/--
Theorem: Any change in structural state (leaf stress)
is reflected in the root hash.
-/
theorem structural_integrity_reflected (id : Nat) (s1 s2 : StressVector) (h : s1 ≠ s2) :
mechanicalHash s1 ≠ mechanicalHash s2 := by
-- This depends on the hash function properties.
-- For XOR-sum it might have collisions, but for Blake3/formal proof we assume
-- injectivity for the semantic model.
-- TODO(lean-port): UNPROVABLE AS STATED. XOR-sum is NOT injective (collisions exist).
-- Weakened theorem: single-component change guarantees hash change.
sorry
/--
Weakened version: a single-component change in stress is reflected in the hash.
XOR is injective in each argument when the other is fixed.
-/
theorem structural_integrity_reflected_single_component
(s1 s2 : StressVector)
(hX : s1.sigmaX ≠ s2.sigmaX)
(hY : s1.sigmaY = s2.sigmaY)
(hZ : s1.sigmaZ = s2.sigmaZ)
(hXY : s1.tauXY = s2.tauXY)
(hYZ : s1.tauYZ = s2.tauYZ)
(hZX : s1.tauZX = s2.tauZX) :
mechanicalHash s1 ≠ mechanicalHash s2 := by
simp [mechanicalHash] at *
intro h_eq
rw [hY, hZ, hXY, hYZ, hZX] at h_eq
have h_cancel : s1.sigmaX.val = s2.sigmaX.val := by
apply (UInt32.xor_right_inj (s2.sigmaY.val ^^^ s2.sigmaZ.val ^^^ s2.tauXY.val ^^^ s2.tauYZ.val ^^^ s2.tauZX.val)).mp
simp [UInt32.xor_comm] at h_eq ⊢
exact h_eq
have h_eq_stress : s1.sigmaX = s2.sigmaX := by
have h1 : s1.sigmaX = ⟨s1.sigmaX.val⟩ := by cases s1.sigmaX; rfl
have h2 : s2.sigmaX = ⟨s2.sigmaX.val⟩ := by cases s2.sigmaX; rfl
rw [h1, h2, h_cancel]
contradiction
end Semantics.StructuralAttestation