    function file(bytes32 what, uint256 data) external auth {
        if (what == "delay") {
            require(data <= MAX_DELAY, "Root/delay-too-long");
            delay = data;
        } else {
            revert("Root/file-unrecognized-param");
        }
        emit File(what, data);
+    uint256 private MIN_DELAY = 2 days ;

    function file(bytes32 what, uint256 data) external auth {
        if (what == "delay") {
            require(data <= MAX_DELAY, "Root/delay-too-long");
+           require(data >= MIN_DELAY, "Root/delay-too-short");

            delay = data;
        } else {
            revert("Root/file-unrecognized-param");
        }
        emit File(what, data);
