Simple, when you click/touch a brick, a message box comes up in which you type in a password and click the "Ok Button". Then there should be a onPasswordFail and onPasswordCorrect events.
Example;
onActivate > Self > Password [cake]
onPasswordFail > Client > CenterPrint [Incorrect]
onPasswordCorrect > Client > CenterPrint [Correct!]
onPasswordCorrect > Namedbrick > Dissappear [5]