Enhanced Standardized Payload System: A Comprehensive Guide

1. Standardized Payload Structure

1.1 Standardized Payload Contract

The StandardizedPayloadStorage contract provides a flexible and generic structure to store, manage, and interact with payloads on-chain. This contract can be extended or adapted for various blockchain applications.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract StandardizedPayloadStorage {
    enum PayloadType { GENERIC, IMAGE, FINANCIAL }

    struct Payload {
        PayloadType payloadType; // The type of payload (generic, image, financial, etc.)
        bytes data; // The actual data, encoded as bytes
        bytes32 hash; // A hash of the data for verification purposes
        address creator; // The creator of the payload
        uint256 timestamp; // The time the payload was created
        bytes executionLogic; // Optional field for any execution logic or references to other payloads
    }

    mapping(uint256 => Payload) public payloads;
    uint256 public payloadCount;

    event PayloadStored(uint256 indexed payloadId, PayloadType indexed payloadType, address indexed creator, uint256 timestamp);

    // Function to store a new payload
    function storePayload(PayloadType payloadType, bytes memory data, bytes memory executionLogic) public {
        payloadCount++;
        bytes32 dataHash = keccak256(data);
        payloads[payloadCount] = Payload({
            payloadType: payloadType,
            data: data,
            hash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp,
            executionLogic: executionLogic
        });

        emit PayloadStored(payloadCount, payloadType, msg.sender, block.timestamp);
    }

    // Function to retrieve a payload by its ID
    function getPayload(uint256 payloadId) public view returns (PayloadType, bytes memory, bytes32, address, uint256, bytes memory) {
        Payload memory p = payloads[payloadId];
        return (p.payloadType, p.data, p.hash, p.creator, p.timestamp, p.executionLogic);
    }

    // Function to verify the integrity of a payload using its hash
    function verifyPayload(uint256 payloadId, bytes memory data) public view returns (bool) {
        Payload memory p = payloads[payloadId];
        return p.hash == keccak256(data);
    }

    // Function to execute logic contained in a payload (if any)
    function executePayload(uint256 payloadId) public returns (bool) {
        Payload memory p = payloads[payloadId];
        require(p.executionLogic.length > 0, "No execution logic provided");
        (bool success, ) = address(this).call(p.executionLogic);
        require(success, "Payload execution failed");
        return success;
    }
}
        

2. Advanced Features

2.1 Dynamic Data Privacy

Introduce dynamic data privacy features that allow for the selective disclosure of payload data. This can be useful in scenarios where sensitive information needs to be protected but selectively shared with authorized parties.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/cryptography/Encryption.sol";

contract DynamicDataPrivacyPayloadStorage is Ownable {
    struct EncryptedPayload {
        bytes encryptedData; // Encrypted data
        bytes32 hash; // Hash of the original data
        address creator;
        uint256 timestamp;
    }

    mapping(uint256 => EncryptedPayload) public payloads;
    uint256 public payloadCount;

    event EncryptedPayloadStored(uint256 indexed payloadId, address indexed creator, uint256 timestamp);

    function storeEncryptedPayload(bytes memory encryptedData, bytes32 dataHash) public onlyOwner {
        payloadCount++;
        payloads[payloadCount] = EncryptedPayload({
            encryptedData: encryptedData,
            hash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp
        });

        emit EncryptedPayloadStored(payloadCount, msg.sender, block.timestamp);
    }

    function decryptPayload(uint256 payloadId, bytes memory decryptionKey) public view returns (bytes memory) {
        EncryptedPayload memory payload = payloads[payloadId];
        // Example decryption (replace with actual decryption logic)
        bytes memory decryptedData = Encryption.decrypt(payload.encryptedData, decryptionKey);
        require(keccak256(decryptedData) == payload.hash, "Decryption failed or data tampered with");
        return decryptedData;
    }
}
        

2.2 Smart Contract Auditing and Compliance

Incorporate built-in auditing and compliance checks within the payload system. This ensures that any payload execution is compliant with predefined regulations or standards, which is especially useful in regulated industries.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/AccessControl.sol";

contract AuditablePayloadStorage is AccessControl {
    bytes32 public constant AUDITOR_ROLE = keccak256("AUDITOR_ROLE");

    enum PayloadType { GENERIC, IMAGE, FINANCIAL }

    struct Payload {
        PayloadType payloadType;
        bytes data;
        bytes32 hash;
        address creator;
        uint256 timestamp;
        bool compliant;
    }

    mapping(uint256 => Payload) public payloads;
    uint256 public payloadCount;

    event PayloadStored(uint256 indexed payloadId, PayloadType indexed payloadType, address indexed creator, uint256 timestamp, bool compliant);

    constructor() {
        _setupRole(AUDITOR_ROLE, msg.sender);
    }

    function storePayload(PayloadType payloadType, bytes memory data, bool compliant) public {
        require(hasRole(AUDITOR_ROLE, msg.sender), "Only auditors can store payloads");
        payloadCount++;
        bytes32 dataHash = keccak256(data);
        payloads[payloadCount] = Payload({
            payloadType: payloadType,
            data: data,
            hash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp,
            compliant: compliant
        });

        emit PayloadStored(payloadCount, payloadType, msg.sender, block.timestamp, compliant);
    }

    function markCompliance(uint256 payloadId, bool complianceStatus) public {
        require(hasRole(AUDITOR_ROLE, msg.sender), "Only auditors can mark compliance");
        payloads[payloadId].compliant = complianceStatus;
    }
}
        

2.3 Integration with Zero-Knowledge Proofs

Enable the use of zero-knowledge proofs (ZKPs) within the payload system to verify certain conditions or computations without revealing sensitive information. This is particularly useful in privacy-focused applications.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "zkp-library/ZKPLibrary.sol";

contract ZeroKnowledgePayloadStorage {
    struct ZKPayload {
        bytes32 proof;
        bytes32 dataHash;
        address creator;
        uint256 timestamp;
    }

    mapping(uint256 => ZKPayload) public payloads;
    uint256 public payloadCount;

    event ZKPayloadStored(uint256 indexed payloadId, address indexed creator, uint256 timestamp);

    function storeZKPayload(bytes32 proof, bytes32 dataHash) public {
        require(ZKPLibrary.verifyProof(proof), "Invalid zero-knowledge proof");
        payloadCount++;
        payloads[payloadCount] = ZKPayload({
            proof: proof,
            dataHash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp
        });

        emit ZKPayloadStored(payloadCount, msg.sender, block.timestamp);
    }

    function verifyPayload(uint256 payloadId) public view returns (bool) {
        ZKPayload memory payload = payloads[payloadId];
        return ZKPLibrary.verifyProof(payload.proof);
    }
}
        

2.4 Support for Non-Fungible and Semi-Fungible Tokens

Enhance the payload system to natively support interactions with both ERC-721 (NFTs) and ERC-1155 (SFTs) tokens, allowing for more complex tokenized applications.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";

contract TokenizedPayloadStorage {
    enum PayloadType { GENERIC, IMAGE, FINANCIAL, NFT, SFT }

    struct Payload {
        PayloadType payloadType;
        bytes data;
        bytes32 hash;
        address creator;
        uint256 timestamp;
        address tokenContract;
        uint256 tokenId;
    }

    mapping(uint256 => Payload) public payloads;
    uint256 public payloadCount;

    event TokenizedPayloadStored(uint256 indexed payloadId, PayloadType indexed payloadType, address indexed creator, uint256 timestamp);

    function storeNFTPayload(address tokenContract, uint256 tokenId, bytes memory data) public {
        require(IERC721(tokenContract).ownerOf(tokenId) == msg.sender, "Not the token owner");
        storePayload(PayloadType.NFT, data, tokenContract, tokenId);
    }

    function storeSFTPayload(address tokenContract, uint256 tokenId, bytes memory data) public {
        require(IERC1155(tokenContract).balanceOf(msg.sender, tokenId) > 0, "Insufficient token balance");
        storePayload(PayloadType.SFT, data, tokenContract, tokenId);
    }

    function storePayload(PayloadType payloadType, bytes memory data, address tokenContract, uint256 tokenId) internal {
        payloadCount++;
        bytes32 dataHash = keccak256(data);
        payloads[payloadCount] = Payload({
            payloadType: payloadType,
            data: data,
            hash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp,
            tokenContract: tokenContract,
            tokenId: tokenId
        });

        emit TokenizedPayloadStored(payloadCount, payloadType, msg.sender, block.timestamp);
    }
}
        

2.5 Decentralized Governance Mechanisms

Implement governance mechanisms that allow users and stakeholders to vote on changes to the payload system, such as adding new features, upgrading contracts, or modifying parameters.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/governance/IGovernor.sol";

contract GovernancePayloadStorage is IGovernor {
    IERC20 public governanceToken;

    struct Proposal {
        uint256 proposalId;
        string description;
        bytes executionLogic;
        uint256 voteCount;
        bool executed;
        mapping(address => bool) voted;
    }

    uint256 public proposalCount;
    mapping(uint256 => Proposal) public proposals;

    event ProposalCreated(uint256 indexed proposalId, string description, address indexed creator);
    event ProposalExecuted(uint256 indexed proposalId, bool success);

    constructor(address tokenAddress) {
        governanceToken = IERC20(tokenAddress);
    }

    function createProposal(string memory description, bytes memory executionLogic) public {
        proposalCount++;
        proposals[proposalCount] = Proposal({
            proposalId: proposalCount,
            description: description,
            executionLogic: executionLogic,
            voteCount: 0,
            executed: false
        });

        emit ProposalCreated(proposalCount, description, msg.sender);
    }

    function vote(uint256 proposalId) public {
        require(!proposals[proposalId].voted[msg.sender], "Already voted");
        uint256 votingPower = governanceToken.balanceOf(msg.sender);
        require(votingPower > 0, "No voting power");

        proposals[proposalId].voteCount += votingPower;
        proposals[proposalId].voted[msg.sender] = true;
    }

    function executeProposal(uint256 proposalId) public {
        Proposal storage proposal = proposals[proposalId];
        require(!proposal.executed, "Proposal already executed");

        (bool success, ) = address(this).call(proposal.executionLogic);
        proposal.executed = success;

        emit ProposalExecuted(proposalId, success);
    }
}
        

2.6 Automated Smart Contract Upgrades

Introduce a proxy pattern for smart contract upgrades that allows the payload system to be updated without disrupting the existing state or functionality.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
import "@openzeppelin/contracts/proxy/ProxyAdmin.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract UpgradeablePayloadStorage is Ownable {
    TransparentUpgradeableProxy public proxy;
    ProxyAdmin public proxyAdmin;

    event Upgraded(address indexed newImplementation);

    constructor(address logic, address admin) {
        proxyAdmin = new ProxyAdmin();
        proxy = new TransparentUpgradeableProxy(logic, address(proxyAdmin), "");
        proxyAdmin.transferOwnership(admin);
    }

    function upgrade(address newImplementation) public onlyOwner {
        proxyAdmin.upgrade(proxy, newImplementation);
        emit Upgraded(newImplementation);
    }
}
        

2.7 Adaptive and Context-Aware Payloads

Create adaptive payloads that can adjust their behavior based on the context, such as market conditions, user actions, or external data sources.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

contract AdaptivePayloadStorage {
    AggregatorV3Interface internal priceFeed;

    struct ContextAwarePayload {
        bytes executionLogic;
        int256 priceThreshold;
        bool aboveThreshold;
    }

    mapping(uint256 => ContextAwarePayload) public payloads;
    uint256 public payloadCount;

    event ContextAwarePayloadStored(uint256 indexed payloadId, int256 priceThreshold, bool aboveThreshold, address indexed creator);
    event ContextAwarePayloadExecuted(uint256 indexed payloadId, bool success);

    constructor(address priceFeedAddress) {
        priceFeed = AggregatorV3Interface(priceFeedAddress);
    }

    function storeContextAwarePayload(bytes memory executionLogic, int256 priceThreshold, bool aboveThreshold) public {
        payloadCount++;
        payloads[payloadCount] = ContextAwarePayload({
            executionLogic: executionLogic,
            priceThreshold: priceThreshold,
            aboveThreshold: aboveThreshold
        });

        emit ContextAwarePayloadStored(payloadCount, priceThreshold, aboveThreshold, msg.sender);
    }

    function executePayload(uint256 payloadId) public {
        ContextAwarePayload memory payload = payloads[payloadId];
        (,int256 price,,,) = priceFeed.latestRoundData();
        bool conditionMet = (payload.aboveThreshold && price >= payload.priceThreshold) || (!payload.aboveThreshold && price < payload.priceThreshold);
        
        require(conditionMet, "Price condition not met");

        (bool success, ) = address(this).call(payload.executionLogic);
        emit ContextAwarePayloadExecuted(payloadId, success);
    }
}
        

2.8 Interoperability with Layer 2 Solutions

Enable the payload system to operate seamlessly with Layer 2 (L2) solutions like Optimism, Arbitrum, and zk-Rollups. This reduces transaction costs and increases throughput while maintaining the security of the Ethereum mainnet.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IL2PayloadBridge {
    function sendPayloadToL2(uint256 payloadId, bytes calldata data) external;
    function receivePayloadFromL2(uint256 payloadId, bytes calldata data) external;
}

contract L2PayloadStorage {
    enum PayloadType { GENERIC, IMAGE, FINANCIAL }

    struct Payload {
        PayloadType payloadType;
        bytes data;
        bytes32 hash;
        address creator;
        uint256 timestamp;
    }

    mapping(uint256 => Payload) public payloads;
    uint256 public payloadCount;

    address public l2Bridge;
    address public l1Bridge;

    event PayloadSentToL2(uint256 indexed payloadId, address indexed sender);
    event PayloadReceivedFromL2(uint256 indexed payloadId, address indexed receiver);

    constructor(address _l2Bridge, address _l1Bridge) {
        l2Bridge = _l2Bridge;
        l1Bridge = _l1Bridge;
    }

    function storePayload(PayloadType payloadType, bytes memory data) public {
        payloadCount++;
        bytes32 dataHash = keccak256(data);
        payloads[payloadCount] = Payload({
            payloadType: payloadType,
            data: data,
            hash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp
        });
    }

    function sendPayloadToL2(uint256 payloadId) public {
        require(payloads[payloadId].creator == msg.sender, "Not the payload creator");
        IL2PayloadBridge(l2Bridge).sendPayloadToL2(payloadId, payloads[payloadId].data);
        emit PayloadSentToL2(payloadId, msg.sender);
    }

    function receivePayloadFromL2(uint256 payloadId, bytes memory data) public {
        require(msg.sender == l1Bridge, "Only L1 bridge can call this");
        payloads[payloadId].data = data;
        emit PayloadReceivedFromL2(payloadId, msg.sender);
    }
}
        

2.9 Incorporation of Machine Learning Models

Allow the payload system to store and execute machine learning models on-chain, enabling smart contracts to make decisions based on trained models.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/utils/math/SafeMath.sol";

contract MLModelStorage {
    using SafeMath for uint256;

    struct MLModel {
        bytes modelData; // Serialized model data
        bytes32 hash; // Hash of the model for integrity verification
        address creator;
        uint256 timestamp;
    }

    mapping(uint256 => MLModel) public models;
    uint256 public modelCount;

    event ModelStored(uint256 indexed modelId, address indexed creator, uint256 timestamp);

    function storeModel(bytes memory modelData) public {
        modelCount++;
        bytes32 modelHash = keccak256(modelData);
        models[modelCount] = MLModel({
            modelData: modelData,
            hash: modelHash,
            creator: msg.sender,
            timestamp: block.timestamp
        });

        emit ModelStored(modelCount, msg.sender, block.timestamp);
    }

    function predict(uint256 modelId, bytes memory inputData) public view returns (bytes memory) {
        MLModel memory model = models[modelId];
        require(keccak256(inputData) == model.hash, "Data integrity failed");
        // Off-chain oracles/processors would handle this in practice.
        bytes memory prediction = _performPrediction(model.modelData, inputData);
        return prediction;
    }

    function _performPrediction(bytes memory modelData, bytes memory inputData) internal pure returns (bytes memory) {
        // Example prediction (replace with actual prediction logic)
        return abi.encodePacked(modelData, inputData);
    }
}
        

2.10 Multi-Party Computation (MPC) Integration

Support Multi-Party Computation (MPC) within the payload system, allowing multiple parties to jointly compute a function while keeping their inputs private.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract MPCPayloadStorage {
    struct MPCPayload {
        bytes[] shares; // Shares of the input data
        bytes32 hash; // Hash of the original data
        address[] participants;
        uint256 timestamp;
    }

    mapping(uint256 => MPCPayload) public payloads;
    uint256 public payloadCount;

    event MPCPayloadStored(uint256 indexed payloadId, address[] participants, uint256 timestamp);

    function storeMPCPayload(bytes[] memory shares, address[] memory participants) public {
        payloadCount++;
        bytes32 dataHash = keccak256(abi.encodePacked(shares));
        payloads[payloadCount] = MPCPayload({
            shares: shares,
            hash: dataHash,
            participants: participants,
            timestamp: block.timestamp
        });

        emit MPCPayloadStored(payloadCount, participants, block.timestamp);
    }

    function executeMPC(uint256 payloadId) public view returns (bytes memory) {
        MPCPayload memory payload = payloads[payloadId];
        require(payload.participants.length == payload.shares.length, "MPC shares mismatch");

        // Example MPC computation (replace with actual MPC logic)
        bytes memory result = _combineShares(payload.shares);
        return result;
    }

    function _combineShares(bytes[] memory shares) internal pure returns (bytes memory) {
        // Example combination of shares (actual MPC would be more complex)
        bytes memory combined;
        for (uint i = 0; i < shares.length; i++) {
            combined = abi.encodePacked(combined, shares[i]);
        }
        return combined;
    }
}
        

2.11 Advanced Tokenomics with Dynamic Payloads

Utilize dynamic payloads to create complex tokenomics models where token behavior and supply mechanisms are influenced by on-chain or off-chain data.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract DynamicTokenomics is ERC20 {
    struct TokenomicsPayload {
        uint256 inflationRate;
        uint256 burnRate;
        bytes executionLogic; // Dynamic execution logic
    }

    TokenomicsPayload public tokenomics;
    address public payloadManager;

    event TokenomicsUpdated(uint256 inflationRate, uint256 burnRate, bytes executionLogic);

    constructor(string memory name, string memory symbol) ERC20(name, symbol) {
        payloadManager = msg.sender;
    }

    function updateTokenomics(uint256 inflationRate, uint256 burnRate, bytes memory executionLogic) public {
        require(msg.sender == payloadManager, "Only payload manager can update tokenomics");
        tokenomics = TokenomicsPayload({
            inflationRate: inflationRate,
            burnRate: burnRate,
            executionLogic: executionLogic
        });

        emit TokenomicsUpdated(inflationRate, burnRate, executionLogic);
    }

    function mintTokens(address to, uint256 amount) public {
        uint256 adjustedAmount = amount.mul(tokenomics.inflationRate).div(100);
        _mint(to, adjustedAmount);
    }

    function burnTokens(uint256 amount) public {
        uint256 adjustedAmount = amount.mul(tokenomics.burnRate).div(100);
        _burn(msg.sender, adjustedAmount);
    }
}
        

2.12 Privacy-Preserving DeFi Applications

Implement privacy-preserving features in DeFi applications using the payload system, ensuring that sensitive user data remains confidential.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";

contract PrivacyDeFi {
    struct EncryptedTransaction {
        bytes encryptedData;
        bytes32 hash;
        address sender;
        address receiver;
        uint256 timestamp;
    }

    mapping(uint256 => EncryptedTransaction) public transactions;
    uint256 public transactionCount;

    event EncryptedTransactionStored(uint256 indexed transactionId, address indexed sender, address indexed receiver, uint256 timestamp);

    function storeEncryptedTransaction(bytes memory encryptedData, address receiver) public {
        transactionCount++;
        bytes32 dataHash = keccak256(encryptedData);
        transactions[transactionCount] = EncryptedTransaction({
            encryptedData: encryptedData,
            hash: dataHash,
            sender: msg.sender,
            receiver: receiver,
            timestamp: block.timestamp
        });

        emit EncryptedTransactionStored(transactionCount, msg.sender, receiver, block.timestamp);
    }

    function decryptTransaction(uint256 transactionId, bytes memory decryptionKey) public view returns (bytes memory) {
        EncryptedTransaction memory txn = transactions[transactionId];
        require(msg.sender == txn.receiver, "Only the receiver can decrypt");
        bytes memory decryptedData = ECDSA.recover(txn.hash, decryptionKey);
        require(keccak256(decryptedData) == txn.hash, "Decryption failed or data tampered with");
        return decryptedData;
    }
}
        

2.13 Interfacing with IoT Devices

Enable payloads to interact with Internet of Things (IoT) devices, allowing smart contracts to trigger actions in the physical world based on data received from sensors or other IoT systems.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IIoTDevice {
    function sendData(bytes calldata data) external;
    function receiveData() external view returns (bytes memory);
}

contract IoTPayloadStorage {
    struct IoTPayload {
        bytes deviceData;
        address deviceAddress;
        uint256 timestamp;
    }

    mapping(uint256 => IoTPayload) public payloads;
    uint256 public payloadCount;

    event IoTPayloadStored(uint256 indexed payloadId, address indexed deviceAddress, uint256 timestamp);

    function storeIoTPayload(address deviceAddress, bytes memory deviceData) public {
        payloadCount++;
        payloads[payloadCount] = IoTPayload({
            deviceData: deviceData,
            deviceAddress: deviceAddress,
            timestamp: block.timestamp
        });

        emit IoTPayloadStored(payloadCount, deviceAddress, block.timestamp);
    }

    function triggerIoTDevice(uint256 payloadId) public {
        IoTPayload memory payload = payloads[payloadId];
        IIoTDevice(payload.deviceAddress).sendData(payload.deviceData);
    }

    function receiveIoTData(uint256 payloadId) public view returns (bytes memory) {
        IoTPayload memory payload = payloads[payloadId];
        return IIoTDevice(payload.deviceAddress).receiveData();
    }
}
        

2.14 Integration with Decentralized Identity Systems

Integrate with decentralized identity (DID) systems to ensure that payloads can be securely tied to verified identities, enhancing trust and security.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/AccessControl.sol";

interface IDIDRegistry {
    function getDIDDocument(address user) external view returns (bytes memory);
}

contract DIDPayloadStorage is AccessControl {
    bytes32 public constant DID_ROLE = keccak256("DID_ROLE");

    struct DIDPayload {
        bytes data;
        bytes32 hash;
        address creator;
        uint256 timestamp;
    }

    mapping(uint256 => DIDPayload) public payloads;
    uint256 public payloadCount;

    IDIDRegistry public didRegistry;

    event DIDPayloadStored(uint256 indexed payloadId, address indexed creator, uint256 timestamp);

    constructor(address _didRegistry) {
        didRegistry = IDIDRegistry(_didRegistry);
        _setupRole(DID_ROLE, msg.sender);
    }

    function storeDIDPayload(bytes memory data) public {
        require(hasRole(DID_ROLE, msg.sender), "Caller is not authorized");
        payloadCount++;
        bytes32 dataHash = keccak256(data);
        payloads[payloadCount] = DIDPayload({
            data: data,
            hash: dataHash,
            creator: msg.sender,
            timestamp: block.timestamp
        });

        emit DIDPayloadStored(payloadCount, msg.sender, block.timestamp);
    }

    function verifyDID(address user) public view returns (bool) {
        bytes memory didDocument = didRegistry.getDIDDocument(user);
        return didDocument.length > 0;
    }
}
        

3. Deployment Instructions

4. Integration Examples

5. Security Considerations

6. Optimization Strategies