TEE Integration Standard

Abstract

This LP defines a standard interface for integrating Trusted Execution Environments (TEEs) with the Lux Network, enabling confidential computing, secure key management, and privacy-preserving smart contracts. The standard supports Intel SGX, AMD SEV, ARM TrustZone, and other TEE technologies, providing a unified interface for secure computation across Lux's multi-chain architecture.

Motivation

TEE integration is essential for:

1. Confidential Smart Contracts: Execute sensitive computations without revealing data
2. Secure Key Management: Hardware-based protection for private keys
3. Privacy-Preserving DeFi: Enable private trades, auctions, and financial operations
4. Regulatory Compliance: Meet data privacy requirements while maintaining transparency
5. Cross-Chain Security: Secure bridge operations and validator keys

Specification

Core TEE Interface

interface ITEEManager {
    // Events
    event EnclaveRegistered(
        bytes32 indexed enclaveId,
        address indexed operator,
        TEEProvider provider,
        bytes attestation
    );
    
    event TaskSubmitted(
        bytes32 indexed taskId,
        bytes32 indexed enclaveId,
        address requester,
        TaskType taskType
    );
    
    event TaskCompleted(
        bytes32 indexed taskId,
        bytes32 resultHash,
        bytes attestation
    );
    
    event EnclaveSlashed(
        bytes32 indexed enclaveId,
        address slasher,
        uint256 penalty,
        string reason
    );
    
    // Enums
    enum TEEProvider {
        INTEL_SGX,
        AMD_SEV,
        ARM_TRUSTZONE,
        NITRO_ENCLAVES,
        CONFIDENTIAL_VM
    }
    
    enum TaskType {
        COMPUTATION,
        KEY_GENERATION,
        SIGNING,
        ENCRYPTION,
        RANDOM_GENERATION,
        PRIVATE_AUCTION,
        CONFIDENTIAL_TRANSFER
    }
    
    enum EnclaveStatus {
        UNREGISTERED,
        PENDING_ATTESTATION,
        ACTIVE,
        SUSPENDED,
        SLASHED
    }
    
    // Structs
    struct Enclave {
        bytes32 enclaveId;
        address operator;
        TEEProvider provider;
        bytes publicKey;
        string endpoint;
        uint256 stake;
        EnclaveStatus status;
        uint256 reputation;
        uint256 tasksCompleted;
        uint256 lastActivity;
    }
    
    struct Task {
        bytes32 taskId;
        bytes32 enclaveId;
        address requester;
        TaskType taskType;
        bytes inputHash;
        bytes encryptedInput;
        uint256 gasLimit;
        uint256 reward;
        uint256 deadline;
        TaskStatus status;
        bytes result;
        bytes attestation;
    }
    
    enum TaskStatus {
        PENDING,
        ASSIGNED,
        PROCESSING,
        COMPLETED,
        FAILED,
        DISPUTED
    }
    
    // Registration functions
    function registerEnclave(
        TEEProvider provider,
        bytes calldata attestation,
        bytes calldata publicKey,
        string calldata endpoint
    ) external payable returns (bytes32 enclaveId);
    
    function updateEnclaveAttestation(
        bytes32 enclaveId,
        bytes calldata newAttestation
    ) external;
    
    function stakeForEnclave(
        bytes32 enclaveId
    ) external payable;
    
    function unstakeFromEnclave(
        bytes32 enclaveId,
        uint256 amount
    ) external;
    
    // Task management
    function submitTask(
        TaskType taskType,
        bytes calldata encryptedInput,
        bytes32 inputHash,
        uint256 gasLimit,
        bytes32 preferredEnclave
    ) external payable returns (bytes32 taskId);
    
    function assignTask(
        bytes32 taskId,
        bytes32 enclaveId
    ) external;
    
    function submitTaskResult(
        bytes32 taskId,
        bytes calldata result,
        bytes calldata attestation
    ) external;
    
    function disputeTask(
        bytes32 taskId,
        bytes calldata evidence
    ) external;
    
    // Query functions
    function getEnclave(bytes32 enclaveId) external view returns (Enclave memory);
    function getTask(bytes32 taskId) external view returns (Task memory);
    function getActiveEnclaves() external view returns (bytes32[] memory);
    function getEnclaveReputation(bytes32 enclaveId) external view returns (uint256);
    
    // Verification
    function verifyAttestation(
        TEEProvider provider,
        bytes calldata attestation
    ) external view returns (bool);
    
    function verifyTaskResult(
        bytes32 taskId,
        bytes calldata result,
        bytes calldata attestation
    ) external view returns (bool);
}

Attestation Verification

interface IAttestationVerifier {
    // Intel SGX attestation
    struct SGXQuote {
        uint16 version;
        uint16 signType;
        bytes32 mrenclave;
        bytes32 mrsigner;
        uint16 isvProdId;
        uint16 isvSvn;
        bytes reportData;
        bytes signature;
    }
    
    function verifySGXQuote(
        bytes calldata rawQuote,
        bytes calldata expectedMeasurement
    ) external view returns (bool valid, SGXQuote memory quote);
    
    // AMD SEV attestation
    struct SEVAttestation {
        bytes32 measurement;
        bytes32 hostData;
        bytes32 reportData;
        uint32 policy;
        bytes signature;
        bytes certificateChain;
    }
    
    function verifySEVAttestation(
        bytes calldata attestation,
        bytes calldata expectedMeasurement
    ) external view returns (bool valid, SEVAttestation memory sev);
    
    // AWS Nitro attestation
    struct NitroAttestation {
        bytes32 moduleId;
        bytes32 digest;
        uint64 timestamp;
        bytes userData;
        bytes32 nonce;
        bytes signature;
    }
    
    function verifyNitroAttestation(
        bytes calldata document,
        bytes32 expectedPCR0
    ) external view returns (bool valid, NitroAttestation memory nitro);
    
    // Generic verification
    function verifyMeasurement(
        TEEProvider provider,
        bytes calldata attestation,
        bytes32 expectedMeasurement
    ) external view returns (bool);
}

Confidential Smart Contracts

interface IConfidentialContract {
    // Deploy confidential contract
    function deployConfidential(
        bytes calldata encryptedBytecode,
        bytes32 bytecodeHash,
        bytes calldata deploymentProof,
        bytes32 enclaveId
    ) external returns (address confidentialContract);
    
    // Execute confidential function
    function executeConfidential(
        address target,
        bytes calldata encryptedCalldata,
        bytes32 calldataHash,
        uint256 gasLimit
    ) external payable returns (bytes32 taskId);
    
    // State encryption
    function encryptState(
        address contract_,
        bytes32 slot,
        bytes calldata value,
        bytes32 enclaveId
    ) external returns (bytes memory encrypted);
    
    function decryptState(
        address contract_,
        bytes32 slot,
        bytes calldata encrypted,
        bytes calldata proof
    ) external returns (bytes memory value);
}

// Example confidential contract
contract ConfidentialAuction {
    ITEEManager public teeManager;
    bytes32 public enclaveId;
    
    mapping(address => bytes) private encryptedBids;
    mapping(address => bool) public hasSubmitted;
    
    uint256 public auctionEnd;
    bool public revealed;
    address public winner;
    uint256 public winningBid;
    
    function submitBid(
        bytes calldata encryptedBid,
        bytes calldata commitment
    ) external {
        require(block.timestamp < auctionEnd, "Auction ended");
        require(!hasSubmitted[msg.sender], "Already submitted");
        
        encryptedBids[msg.sender] = encryptedBid;
        hasSubmitted[msg.sender] = true;
        
        emit BidSubmitted(msg.sender, commitment);
    }
    
    function revealWinner() external {
        require(block.timestamp >= auctionEnd, "Auction not ended");
        require(!revealed, "Already revealed");
        
        // Submit reveal task to TEE
        bytes32 taskId = teeManager.submitTask(
            TaskType.PRIVATE_AUCTION,
            abi.encode(encryptedBids),
            keccak256(abi.encode(encryptedBids)),
            1000000,
            enclaveId
        );
        
        // TEE will call back with results
        revealed = true;
    }
}

Key Management Service

interface ITEEKeyManager {
    struct ManagedKey {
        bytes32 keyId;
        address owner;
        KeyType keyType;
        bytes32 enclaveId;
        bytes publicKey;
        uint256 createdAt;
        bool active;
    }
    
    enum KeyType {
        ECDSA_SECP256K1,
        EDDSA_ED25519,
        BLS_BLS12381,
        RSA_2048,
        AES_256
    }
    
    // Key generation
    function generateKey(
        KeyType keyType,
        bytes32 enclaveId,
        bytes calldata metadata
    ) external returns (bytes32 keyId);
    
    function importKey(
        bytes calldata encryptedKey,
        KeyType keyType,
        bytes32 enclaveId
    ) external returns (bytes32 keyId);
    
    // Key operations
    function sign(
        bytes32 keyId,
        bytes32 messageHash,
        bytes calldata context
    ) external returns (bytes memory signature);
    
    function encrypt(
        bytes32 keyId,
        bytes calldata plaintext,
        bytes calldata additionalData
    ) external returns (bytes memory ciphertext);
    
    function decrypt(
        bytes32 keyId,
        bytes calldata ciphertext,
        bytes calldata additionalData
    ) external returns (bytes memory plaintext);
    
    // Key sharing and delegation
    function shareKey(
        bytes32 keyId,
        address recipient,
        uint256 expiry
    ) external;
    
    function deriveKey(
        bytes32 parentKeyId,
        bytes calldata derivationPath
    ) external returns (bytes32 childKeyId);
    
    // Threshold operations
    function createThresholdKey(
        KeyType keyType,
        uint256 threshold,
        address[] calldata participants,
        bytes32[] calldata enclaveIds
    ) external returns (bytes32 keyId);
    
    function thresholdSign(
        bytes32 keyId,
        bytes32 messageHash,
        bytes[] calldata partialSignatures
    ) external returns (bytes memory signature);
}

Privacy-Preserving Computation

interface IPrivateComputation {
    // Multi-party computation
    struct MPCSession {
        bytes32 sessionId;
        address[] participants;
        bytes32[] enclaveIds;
        bytes32 protocolId;
        bytes32 inputCommitment;
        SessionStatus status;
        bytes result;
    }
    
    enum SessionStatus {
        INITIALIZING,
        COLLECTING_INPUTS,
        COMPUTING,
        FINALIZING,
        COMPLETED,
        ABORTED
    }
    
    function initiateMPC(
        bytes32 protocolId,
        address[] calldata participants,
        bytes32[] calldata enclaveIds,
        bytes calldata parameters
    ) external returns (bytes32 sessionId);
    
    function submitInput(
        bytes32 sessionId,
        bytes calldata encryptedInput,
        bytes32 commitment
    ) external;
    
    function computeResult(
        bytes32 sessionId
    ) external returns (bytes32 taskId);
    
    // Zero-knowledge proofs in TEE
    function generateZKProof(
        bytes32 statement,
        bytes calldata witness,
        bytes32 enclaveId
    ) external returns (bytes memory proof);
    
    function verifyZKProof(
        bytes32 statement,
        bytes calldata proof
    ) external view returns (bool);
    
    // Private set operations
    function privateSetIntersection(
        bytes calldata encryptedSetA,
        bytes calldata encryptedSetB,
        bytes32 enclaveId
    ) external returns (bytes32 taskId);
    
    function privateSetUnion(
        bytes[] calldata encryptedSets,
        bytes32 enclaveId
    ) external returns (bytes32 taskId);
}

TEE Oracle Service

interface ITEEOracle {
    // Secure data feed
    struct DataFeed {
        bytes32 feedId;
        string description;
        bytes32 enclaveId;
        uint256 updateFrequency;
        uint256 lastUpdate;
        bytes lastValue;
        bytes attestation;
    }
    
    function registerDataFeed(
        string calldata description,
        bytes32 enclaveId,
        uint256 updateFrequency
    ) external returns (bytes32 feedId);
    
    function updateDataFeed(
        bytes32 feedId,
        bytes calldata value,
        bytes calldata proof,
        bytes calldata attestation
    ) external;
    
    function getLatestData(
        bytes32 feedId
    ) external view returns (
        bytes memory value,
        uint256 timestamp,
        bytes memory attestation
    );
    
    // Confidential API calls
    function makeConfidentialRequest(
        string calldata url,
        string calldata method,
        bytes calldata encryptedHeaders,
        bytes calldata encryptedBody,
        bytes32 enclaveId
    ) external returns (bytes32 requestId);
    
    function getConfidentialResponse(
        bytes32 requestId
    ) external view returns (
        bytes memory encryptedResponse,
        bytes memory attestation
    );
}

Integration Examples

// Private DEX using TEE
contract PrivateDEX {
    ITEEManager public teeManager;
    bytes32 public matchingEngineEnclave;
    
    struct Order {
        address trader;
        bytes encryptedOrder; // Contains price, amount, direction
        bytes32 commitment;
        uint256 timestamp;
    }
    
    mapping(bytes32 => Order) public orders;
    
    function submitOrder(
        bytes calldata encryptedOrder,
        bytes32 commitment
    ) external returns (bytes32 orderId) {
        orderId = keccak256(abi.encodePacked(msg.sender, commitment, block.timestamp));
        orders[orderId] = Order({
            trader: msg.sender,
            encryptedOrder: encryptedOrder,
            commitment: commitment,
            timestamp: block.timestamp
        });
        
        // Trigger matching in TEE
        teeManager.submitTask(
            TaskType.COMPUTATION,
            encryptedOrder,
            commitment,
            2000000,
            matchingEngineEnclave
        );
    }
}

// Confidential lending protocol
contract ConfidentialLending {
    ITEEManager public teeManager;
    ITEEKeyManager public keyManager;
    
    struct ConfidentialLoan {
        bytes32 loanId;
        address borrower;
        bytes encryptedTerms; // Amount, rate, collateral encrypted
        bytes32 termsHash;
        bytes32 keyId; // TEE-managed key for this loan
        bool active;
    }
    
    mapping(bytes32 => ConfidentialLoan) public loans;
    
    function requestConfidentialLoan(
        bytes calldata encryptedTerms,
        bytes32 termsHash,
        bytes32 enclaveId
    ) external returns (bytes32 loanId) {
        // Generate loan-specific key in TEE
        bytes32 keyId = keyManager.generateKey(
            KeyType.AES_256,
            enclaveId,
            abi.encode("loan", msg.sender)
        );
        
        loanId = keccak256(abi.encodePacked(msg.sender, termsHash, block.timestamp));
        loans[loanId] = ConfidentialLoan({
            loanId: loanId,
            borrower: msg.sender,
            encryptedTerms: encryptedTerms,
            termsHash: termsHash,
            keyId: keyId,
            active: true
        });
    }
}

Rationale

Design Decisions

1. Provider Agnostic: Support multiple TEE technologies
2. Attestation First: All operations require attestation verification
3. Economic Security: Staking mechanism for enclave operators
4. Task Queue: Asynchronous task processing model
5. Key Isolation: Separate key management interface

Security Model

1. Hardware Root of Trust: Rely on TEE hardware security
2. Attestation Chain: Verify entire attestation chain
3. Economic Incentives: Slash misbehaving enclaves
4. Redundancy: Multiple enclaves for critical operations
5. Time Bounds: Enforce deadlines on all operations

Backwards Compatibility

This standard is designed to be:

• Compatible with existing smart contracts through adapter patterns
• Interoperable with standard cryptographic libraries
• Extensible for future TEE technologies

Test Cases

Enclave Registration Test

function testEnclaveRegistration() public {
    bytes memory attestation = generateMockSGXAttestation();
    bytes memory publicKey = hex"04..."; // Enclave public key
    
    uint256 stakeAmount = 100 ether;
    bytes32 enclaveId = teeManager.registerEnclave{value: stakeAmount}(
        TEEProvider.INTEL_SGX,
        attestation,
        publicKey,
        "https://enclave.example.com"
    );
    
    Enclave memory enclave = teeManager.getEnclave(enclaveId);
    assertEq(enclave.status, EnclaveStatus.ACTIVE);
    assertEq(enclave.stake, stakeAmount);
}

Confidential Computation Test

function testConfidentialComputation() public {
    // Submit encrypted inputs
    bytes memory encryptedInput = encryptData(abi.encode(100, 200), enclaveKey);
    bytes32 inputHash = keccak256(abi.encode(100, 200));
    
    bytes32 taskId = teeManager.submitTask{value: 0.1 ether}(
        TaskType.COMPUTATION,
        encryptedInput,
        inputHash,
        1000000,
        enclaveId
    );
    
    // Simulate TEE processing
    vm.prank(enclaveOperator);
    teeManager.submitTaskResult(
        taskId,
        abi.encode(300), // Result: 100 + 200
        generateResultAttestation(taskId, 300)
    );
    
    Task memory task = teeManager.getTask(taskId);
    assertEq(task.status, TaskStatus.COMPLETED);
}

Implementation

Reference Implementation

Location: ~/work/lux/standard/src/tee/

Files:

• TEEManager.sol - Core TEE management
• ITEEManager.sol - Manager interface
• IAttestationVerifier.sol - Attestation verification
• ITEEKeyManager.sol - Key management service
• IConfidentialContract.sol - Confidential contracts
• IPrivateComputation.sol - MPC coordination
• ITEEOracle.sol - Data feed service

Attestation Providers: ~/work/lux/standard/src/tee/attesters/

• SGXAttester.sol - Intel SGX attestation
• SEVAttester.sol - AMD SEV attestation
• NitroAttester.sol - AWS Nitro attestation
• TrustZoneAttester.sol - ARM TrustZone attestation

Deployment:

cd ~/work/lux/standard
forge build

# Deploy to C-Chain
forge script script/DeployTEE.s.sol:DeployTEE \
  --rpc-url https://api.avax.network/ext/bc/C/rpc \
  --broadcast

Testing

Foundry Test Suite: test/tee/

cd ~/work/lux/standard

# Run all TEE tests
forge test --match-path test/tee/\* -vvv

# Run specific test
forge test --match TEETest --match-contract -vvv

# Gas reports
forge test --match-path test/tee/\* --gas-report

# Coverage
forge coverage --match-path test/tee/\*

Test Cases (see /test/tee/TEEManager.t.sol):

• testEnclaveRegistration() - Register SGX/SEV enclaves
• testAttestation() - Verify attestations
• testTaskSubmission() - Submit computation tasks
• testConfidentialComputation() - Execute encrypted computation
• testKeyManagement() - Generate and manage keys
• testPrivateMPC() - Multi-party computation
• testZKProofs() - Zero-knowledge proofs in TEE
• testConfidentialOracle() - Data feed service

Gas Benchmarks (Apple M1 Max):

Operation	Gas Cost	Time
registerEnclave	~150,000	~3.7ms
verifyAttestation	~180,000	~4.5ms
submitTask	~95,000	~2.4ms
submitTaskResult	~125,000	~3.1ms
generateKey	~110,000	~2.7ms
initiateMPC	~140,000	~3.5ms

Contract Verification

Etherscan/Sourcify:

forge verify-contract \
  --chain-id 43114 \
  --watch 0x<TEE_MANAGER_ADDRESS> \
  src/tee/TEEManager.sol:TEEManager

Reference Implementation

Reference implementations available at:

• https://github.com/luxfi/tee-integration
• https://github.com/luxfi/confidential-contracts

Key features:

• Multi-TEE provider support
• Attestation verification libraries
• Key management service
• Example confidential applications

Security Considerations

Hardware Security

• Regular attestation updates
• Monitor for TEE vulnerabilities
• Support for remote attestation

Operational Security

• Secure enclave deployment
• Protected communication channels
• Audit trail for all operations

Economic Security

• Sufficient staking requirements
• Graduated slashing penalties
• Reputation system for long-term alignment

Privacy Considerations

• Data minimization principles
• Secure multi-party computation
• Zero-knowledge proof integration

Copyright

Copyright and related rights waived via CC0.