Duplicate Receipt Prevention

duplicate-receipt-prevention · receipt-attestation · 550 B runtime · registry-info

scores

• usefulness: 85
• safety: 90
• liveness: 90
• authenticity: 85
• extensibility: 75
• bytecodeDiscipline: 90
• practical: 87

source

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

contract AnchoredReceiptChain {
    bytes32 public root;
    bytes32[] internal receipts;
    mapping(bytes32 => bool) private seen;

    event Anchored(uint256 indexed receiptId, bytes32 indexed receiptHash, bytes32 newRoot);

    function attest(bytes32 receiptHash) external returns (uint256 receiptId) {
        require(!seen[receiptHash]);
        seen[receiptHash] = true;
        receiptId = receipts.length;
        receipts.push(receiptHash);
        root = keccak256(abi.encodePacked(root, receiptHash));
        emit Anchored(receiptId, receiptHash, root);
    }

    function verify(uint256 receiptId, bytes32 receiptHash) external view returns (bool) {
        return receiptId < receipts.length && receipts[receiptId] == receiptHash;
    }
}

published

published on mainnet · 0x4c6395b46ac841BE7fC4ce599F869E8f67AB6624 · tx 0x0ee5e26cc7b60d6f… · tempo (4217) · mainnet

published on testnet · 0xe9337179F9AAf8C06ec725B37e65fA3d7b5A143C · tx 0x78ccc0e8d37e171b… · tempo (42431) · testnet