HashCheckpoint.sol

pragma solidity^0.5.0;

contract HashCheckpoint {
    
    mapping(address => bytes32) public checkpointHash;
    
    event LogSuccess(bool registered);
    
    function registerHash(bytes32 _latestHash) external {
        checkpointHash[msg.sender] = _latestHash;
        emit LogSuccess(true);
    } 
    
}