BrightID.sol

pragma solidity ^0.6.3;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.sol";

contract BrightID is Ownable {

    event Verified(address indexed addr);
    event Revoked(address indexed addr);
    mapping(address => bool) public verifications;
    mapping(address => address) public history;

    function verify(address addr, address revoked) public onlyOwner
    {
        require(history[addr]!=address(0), "address is verified before");
        require(addr!=revoked, "revoked is equal with address");
        verifications[addr] = true;
        verifications[revoked] = false;
        history[addr] = revoked;
        emit Verified(addr);
        emit Revoked(addr);
    }

}