Smart Contracts

CrowdProof deploys 5 core contracts to EVM-compatible chains. All contracts use Solidity 0.8.24, are built with Foundry, and follow the upgradeable proxy pattern.

Contract Overview

Contract	Purpose	Key Roles
DIDRegistry	Register and resolve DIDs	REGISTRAR_ROLE
ReputationOracle	Store score commitments, verify ZK proofs	ORACLE_ROLE, GOVERNANCE_ROLE
CredentialVerifier	Verify credentials on-chain	ISSUER_ROLE
PaymentEscrow	Handle API access payments	ADMIN_ROLE
GovernanceToken	DAO governance (ERC-20 + voting)	Token holders

DIDRegistry

Manages the mapping between wallet addresses and Decentralized Identifiers.

interface IDIDRegistry {
    function registerDID(string calldata did) external;
    function resolveDID(address wallet) external view returns (string memory);
    function updateDIDDocument(string calldata did, string calldata document) external;
    function deactivateDID(string calldata did) external;

    event DIDRegistered(address indexed wallet, string did);
    event DIDUpdated(string indexed did, string document);
    event DIDDeactivated(string indexed did);
}

ReputationOracle

Stores Merkle roots of score batches and verifies Groth16 ZK proofs.

interface IReputationOracle {
    function commitScores(bytes32 merkleRoot, uint256 batchId) external;
    function getLatestRoot() external view returns (bytes32);
    function verifyProof(
        bytes calldata proof,
        uint256 threshold,
        ScoreCategory category
    ) external view returns (bool);

    event ScoresCommitted(bytes32 indexed merkleRoot, uint256 batchId, uint256 timestamp);
    event ProofVerified(address indexed verifier, ScoreCategory category, bool result);
}

Score Categories (on-chain enum)

enum ScoreCategory {
    DEFI_LENDING,
    DEX_TRADING,
    GOVERNANCE,
    NFT,
    SOCIAL,
    CREDIT_HISTORY
}

CredentialVerifier

Validates Verifiable Credentials issued off-chain against on-chain records.

interface ICredentialVerifier {
    function issueCredential(
        string calldata did,
        bytes32 credentialHash,
        uint256 expirationDate
    ) external;
    function verifyCredential(
        string calldata did,
        bytes32 credentialHash
    ) external view returns (bool valid, uint256 issuedAt, uint256 expiresAt);
    function revokeCredential(string calldata did, bytes32 credentialHash) external;

    event CredentialIssued(string indexed did, bytes32 credentialHash);
    event CredentialRevoked(string indexed did, bytes32 credentialHash);
}

PaymentEscrow

Handles ETH/ERC-20 payments for premium API tier upgrades.

interface IPaymentEscrow {
    function deposit(address token, uint256 amount) external payable;
    function withdraw(address token, uint256 amount) external;
    function getBalance(address user, address token) external view returns (uint256);

    event Deposited(address indexed user, address token, uint256 amount);
    event Withdrawn(address indexed user, address token, uint256 amount);
}

GovernanceToken

ERC-20 token with ERC-20Votes extension for on-chain governance.

interface IGovernanceToken {
    // Standard ERC-20 + ERC-20Votes
    function delegate(address delegatee) external;
    function getVotes(address account) external view returns (uint256);
    function getPastVotes(address account, uint256 timepoint) external view returns (uint256);
}

Governance controls:

• Scoring model parameter changes (decay rate, category weights)
• Fee structure modifications
• Dispute escalation resolution
• Contract upgrades (via proxy admin)

Access Control

All contracts use OpenZeppelin's AccessControl with the following roles:

Role	Granted To	Permissions
DEFAULT_ADMIN_ROLE	Deployer multisig	Grant/revoke roles, upgrade contracts
ORACLE_ROLE	Backend service	Commit score Merkle roots
REGISTRAR_ROLE	Backend service	Register DIDs on behalf of users
ISSUER_ROLE	Authorized credential issuers	Issue on-chain credentials
GOVERNANCE_ROLE	DAO (timelock)	Modify protocol parameters

Build & Test

cd contracts/
forge build          # Compile
forge test           # Run tests
forge test -vvvv     # Verbose test output with traces

Deployment

Contracts are deployed via Foundry scripts. See the deployment guide for chain-specific instructions.