coreth/contracts/PostQuantumVerifier.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

/**
 * @title PostQuantumVerifier
 * @notice Contract for verifying post-quantum signatures using precompiled contracts
 * @dev Uses Lux network's post-quantum precompiles for FALCON and Dilithium verification
 */
contract PostQuantumVerifier {
    
    // Precompile addresses for post-quantum signatures
    address constant FALCON_VERIFY = 0x0000000000000000000000000000000000000100;
    address constant FALCON_RECOVER = 0x0000000000000000000000000000000000000101;
    address constant DILITHIUM_VERIFY = 0x0000000000000000000000000000000000000102;
    address constant ETH_FALCON_VERIFY = 0x0000000000000000000000000000000000000103;
    address constant ETH_DILITHIUM_VERIFY = 0x0000000000000000000000000000000000000104;
    
    // Events
    event FalconVerified(address indexed verifier, bytes32 messageHash, bool valid);
    event DilithiumVerified(address indexed verifier, bytes32 messageHash, bool valid);
    event AddressRecovered(address indexed recovered, bytes32 messageHash);
    
    /**
     * @notice Verify a FALCON-512 signature (NIST-compliant)
     * @param signature The FALCON signature
     * @param message The message that was signed
     * @param publicKey The FALCON public key (897 bytes)
     * @return valid True if signature is valid
     */
    function verifyFalcon(
        bytes memory signature,
        bytes memory message,
        bytes memory publicKey
    ) public returns (bool valid) {
        // ABI encode the parameters for the precompile
        bytes memory input = abi.encode(signature, message, publicKey);
        
        // Call the FALCON verify precompile
        (bool success, bytes memory result) = FALCON_VERIFY.staticcall(input);
        
        if (success && result.length == 32) {
            valid = uint256(bytes32(result)) == 1;
            emit FalconVerified(msg.sender, keccak256(message), valid);
        }
        
        return valid;
    }
    
    /**
     * @notice Verify an ETH-optimized FALCON signature (uses Keccak instead of SHAKE)
     * @param messageHash The hash of the message (32 bytes)
     * @param salt The signature salt (40 bytes)
     * @param s2 The s2 component of signature (compacted format)
     * @param ntth The public key in NTT domain (compacted format)
     * @return valid True if signature is valid
     */
    function verifyETHFalcon(
        bytes32 messageHash,
        bytes memory salt,
        uint256[] memory s2,
        uint256[] memory ntth
    ) public returns (bool valid) {
        require(salt.length == 40, "Invalid salt length");
        require(s2.length == 32, "Invalid s2 length");
        require(ntth.length == 32, "Invalid public key length");
        
        // Pack the data for ETH-optimized format
        bytes memory input = abi.encodePacked(messageHash, salt);
        
        // Add compacted s2
        for (uint i = 0; i < s2.length; i++) {
            input = abi.encodePacked(input, s2[i]);
        }
        
        // Add compacted ntth (public key in NTT domain)
        for (uint i = 0; i < ntth.length; i++) {
            input = abi.encodePacked(input, ntth[i]);
        }
        
        // Call the ETH-optimized FALCON verify precompile
        (bool success, bytes memory result) = ETH_FALCON_VERIFY.staticcall(input);
        
        if (success && result.length == 32) {
            valid = uint256(bytes32(result)) == 1;
            emit FalconVerified(msg.sender, messageHash, valid);
        }
        
        return valid;
    }
    
    /**
     * @notice Recover an address from a FALCON signature (EPERVIER variant)
     * @param messageHash The hash of the message
     * @param salt The signature salt (40 bytes)
     * @param signature The FALCON signature with recovery
     * @return recovered The recovered Ethereum address
     */
    function recoverFalconAddress(
        bytes32 messageHash,
        bytes memory salt,
        bytes memory signature
    ) public returns (address recovered) {
        require(salt.length == 40, "Invalid salt length");
        
        // Pack the input
        bytes memory input = abi.encodePacked(messageHash, salt, signature);
        
        // Call the FALCON recover precompile
        (bool success, bytes memory result) = FALCON_RECOVER.staticcall(input);
        
        if (success && result.length == 32) {
            recovered = address(uint160(uint256(bytes32(result))));
            emit AddressRecovered(recovered, messageHash);
        }
        
        return recovered;
    }
    
    /**
     * @notice Verify a Dilithium3 signature (NIST-compliant)
     * @param signature The Dilithium signature (3293 bytes)
     * @param message The message that was signed
     * @param publicKey The Dilithium public key (1952 bytes)
     * @return valid True if signature is valid
     */
    function verifyDilithium(
        bytes memory signature,
        bytes memory message,
        bytes memory publicKey
    ) public returns (bool valid) {
        require(signature.length == 3293, "Invalid signature length");
        require(publicKey.length == 1952, "Invalid public key length");
        
        // ABI encode the parameters for the precompile
        bytes memory input = abi.encode(signature, message, publicKey);
        
        // Call the Dilithium verify precompile
        (bool success, bytes memory result) = DILITHIUM_VERIFY.staticcall(input);
        
        if (success && result.length == 32) {
            valid = uint256(bytes32(result)) == 1;
            emit DilithiumVerified(msg.sender, keccak256(message), valid);
        }
        
        return valid;
    }
    
    /**
     * @notice Verify an ETH-optimized Dilithium signature
     * @param messageHash The hash of the message
     * @param signatureData The packed signature and public key data
     * @return valid True if signature is valid
     */
    function verifyETHDilithium(
        bytes32 messageHash,
        bytes memory signatureData
    ) public returns (bool valid) {
        // Pack the input
        bytes memory input = abi.encodePacked(messageHash, signatureData);
        
        // Call the ETH-optimized Dilithium verify precompile
        (bool success, bytes memory result) = ETH_DILITHIUM_VERIFY.staticcall(input);
        
        if (success && result.length == 32) {
            valid = uint256(bytes32(result)) == 1;
            emit DilithiumVerified(msg.sender, messageHash, valid);
        }
        
        return valid;
    }
    
    /**
     * @notice Check if an address has been quantum-secured
     * @dev This would integrate with a registry of quantum-secured addresses
     */
    mapping(address => bool) public quantumSecured;
    mapping(address => bytes) public falconPublicKeys;
    mapping(address => bytes) public dilithiumPublicKeys;
    
    /**
     * @notice Register a FALCON public key for an address
     * @param publicKey The FALCON public key to register
     */
    function registerFalconKey(bytes memory publicKey) public {
        require(publicKey.length == 897, "Invalid FALCON public key length");
        falconPublicKeys[msg.sender] = publicKey;
        quantumSecured[msg.sender] = true;
    }
    
    /**
     * @notice Register a Dilithium public key for an address
     * @param publicKey The Dilithium public key to register
     */
    function registerDilithiumKey(bytes memory publicKey) public {
        require(publicKey.length == 1952, "Invalid Dilithium public key length");
        dilithiumPublicKeys[msg.sender] = publicKey;
        quantumSecured[msg.sender] = true;
    }
    
    /**
     * @notice Execute a transaction with FALCON signature verification
     * @param target The target contract
     * @param data The transaction data
     * @param signature The FALCON signature
     * @param signer The address that should have signed
     */
    function executeWithFalcon(
        address target,
        bytes memory data,
        bytes memory signature,
        address signer
    ) public returns (bool success, bytes memory returnData) {
        // Get the registered FALCON public key
        bytes memory publicKey = falconPublicKeys[signer];
        require(publicKey.length > 0, "No FALCON key registered");
        
        // Verify the signature
        bytes32 messageHash = keccak256(abi.encodePacked(target, data, block.number));
        bytes memory message = abi.encodePacked(messageHash);
        
        bool valid = verifyFalcon(signature, message, publicKey);
        require(valid, "Invalid FALCON signature");
        
        // Execute the transaction
        (success, returnData) = target.call(data);
    }
}