feat(lighter): add experimental gnark PLONK proof assertion

examples/lighter/README.md

@@ -37,6 +37,10 @@ The funds-custody outflow rate limit is a separate, independently deployable ass
   drain past a rolling-window TVL fraction during normal operation; the breaker stands down in desert
   mode so it never blocks the mass exits the escape hatch exists to enable. Deploy one instance per
   watched ERC-20 token.
+- **Experimental batch-proof verification** (`LighterBatchProofAssertion`) — re-verifies the
+  one-public-input gnark BN254 PLONK proof attached to each `verifyBatch` call using the executor's
+  compiled-in VK registry. It is bound to the configured Lighter proxy and fails closed on malformed
+  calldata, an unknown VK, or a rejected proof.
 
 ## Files
 
@@ -46,6 +50,7 @@ The funds-custody outflow rate limit is a separate, independently deployable ass
 - `src/LighterBridgeHelpers.sol` — fork-aware reads.
 - `src/LighterBridgeAssertion.sol` — state-machine + desert-mode bundle (trigger wiring + invariants).
 - `src/LighterOutflowCircuitBreaker.sol` — standalone rolling-window collateral outflow breaker.
+- `src/LighterBatchProofAssertion.sol` — Experimental registry-backed gnark PLONK batch-proof guard.
 - `test/LighterBridgeAssertion.t.sol` — honest + malicious behavior per state-machine invariant.
 - `test/LighterOutflowCircuitBreaker.t.sol` — breaker decision logic + constructor guards.
 

examples/lighter/src/LighterBatchProofAssertion.sol

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.13;
+
+import {Assertion} from "credible-std/Assertion.sol";
+import {PhEvm} from "credible-std/PhEvm.sol";
+import {AssertionSpec} from "credible-std/SpecRecorder.sol";
+
+/// @title LighterBatchProofAssertion
+/// @notice Independently verifies Lighter's submitted gnark PLONK batch proof.
+/// @dev This experimental assertion is deliberately bound to one L1 proxy and
+///      one compiled-in verifier key. It validates the matching call context,
+///      then checks the batch commitment and proof extracted from verifyBatch.
+contract LighterBatchProofAssertion is Assertion {
+    bytes4 internal constant VERIFY_BATCH_SELECTOR = 0x23ff50e1;
+    bytes32 internal constant LIGHTER_GNARK_PLONK_VK_ID =
+        0x7856ff107f35077ed23aa1cbd1a4ec95204585dc675e0d3632231c49e48109d0;
+
+    address public immutable lighterProxy;
+
+    /// @notice `StoredBatchInfo` has eleven static ABI words in the pinned Lighter ABI.
+    /// @dev Words are retained verbatim because this assertion only needs the final commitment.
+    struct StoredBatchInfo {
+        bytes32[11] words;
+    }
+
+    constructor(address lighterProxy_) {
+        require(lighterProxy_ != address(0), "LighterBatchProof: zero proxy");
+        lighterProxy = lighterProxy_;
+        registerAssertionSpec(AssertionSpec.Experimental);
+    }
+
+    function triggers() external view override {
+        registerFnCallTrigger(this.assertBatchProof.selector, VERIFY_BATCH_SELECTOR);
+    }
+
+    /// @notice Verifies the proof submitted with the exact triggering batch.
+    /// @dev Rejects calls from any adopter other than the configured Lighter proxy,
+    ///      malformed verifyBatch calldata, and algebraically invalid proofs.
+    function assertBatchProof() external view {
+        require(ph.getAssertionAdopter() == lighterProxy, "LighterBatchProof: wrong adopter");
+        PhEvm.TriggerContext memory ctx = ph.context();
+        bytes memory input = ph.callinputAt(ctx.callStart);
+        require(input.length >= 4, "LighterBatchProof: malformed calldata");
+        require(bytes4(input) == VERIFY_BATCH_SELECTOR, "LighterBatchProof: wrong selector");
+
+        (StoredBatchInfo memory batch, bytes memory proof) = abi.decode(_withoutSelector(input), (StoredBatchInfo, bytes));
+        require(
+            ph.verifyGnarkPlonkProof(proof, batch.words[10], LIGHTER_GNARK_PLONK_VK_ID),
+            "LighterBatchProof: invalid proof"
+        );
+    }
+
+    function _withoutSelector(bytes memory input) private pure returns (bytes memory args) {
+        args = new bytes(input.length - 4);
+        for (uint256 i; i < args.length; ++i) args[i] = input[i + 4];
+    }
+}

src/PhEvm.sol

@@ -540,6 +540,24 @@ interface PhEvm {
     /// @return ctx The inflow rate-of-change context for the current invocation.
     function inflowRate() external view returns (FlowRateContext memory ctx);
 
+    // ---------------------------------------------------------------
+    //  Experimental: gnark BN254 PLONK verification
+    // ---------------------------------------------------------------
+
+    /// @notice Verifies a registry-backed gnark BN254 PLONK proof.
+    /// @dev EXPERIMENTAL: requires registerAssertionSpec(AssertionSpec.Experimental).
+    ///      The executor accepts only compiled-in verifier-key identifiers; callers
+    ///      cannot provide verifier-key bytes. This currently supports the demonstrated
+    ///      one-public-input gnark BN254 PLONK layout.
+    /// @param proof The Solidity-encoded gnark proof.
+    /// @param commitment The sole public input before BN254 scalar reduction.
+    /// @param verifierKeyId The immutable registry identifier for the verifier key.
+    /// @return valid False when the proof is well-formed but algebraically invalid.
+    function verifyGnarkPlonkProof(bytes calldata proof, bytes32 commitment, bytes32 verifierKeyId)
+        external
+        view
+        returns (bool valid);
+
     // ---------------------------------------------------------------
     //  V2: Anomaly detection
     // ---------------------------------------------------------------