pragma solidity ^0.8.4;

contract MessageDB {
    mapping(address => string) public latestHash;
    event HashSubmitted(address signer, string messageHash);

    constructor() {}

    function submitSignature(string calldata _messageHash) external {
        latestHash[msg.sender] = _messageHash;
        emit HashSubmitted(msg.sender, _messageHash);
    }
}

{
  "compilationTarget": {
    "MessageDB.sol": "MessageDB"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}