Receipt Commit-Reveal Log

receipt-commit-reveal-log · receipt-attestation · 1017 B runtime · registry-info

scores

• usefulness: 8
• safety: 9
• liveness: 9
• authenticity: 6
• extensibility: 4
• bytecodeDiscipline: 10
• practical: 8

source

pragma solidity ^0.8.13;

contract ReceiptCommitReveal {
    event Committed(bytes32 indexed hash, address indexed committer, uint256 blockNumber);
    event Revealed(bytes32 indexed hash, address indexed revealer, bytes receipt);

    uint256 public immutable deadline;
    mapping(bytes32 => uint256) private _records;

    constructor(uint256 deadline_) {
        deadline = deadline_;
    }

    function commit(bytes32 hash) external {
        require(block.timestamp < deadline, "deadline passed");
        require(_records[hash] == 0, "already committed");
        _records[hash] = block.number;
        emit Committed(hash, msg.sender, block.number);
    }

    function reveal(bytes calldata receipt) external {
        bytes32 hash = keccak256(receipt);
        uint256 rec = _records[hash];
        require(rec != 0, "not committed");
        require(block.number > rec, "wait one block");
        require((rec & (1 << 255)) == 0, "already revealed");
        _records[hash] = rec | (1 << 255);
        emit Revealed(hash, msg.sender, receipt);
    }
}