One of three methods in choosing random numbers is used for each of the Lottery's games. These are burned on to the "read only" memory of a microchip. The microchips are secured in the systems' central processing unit, and a protective seal makes tampering impossible. Access to the room and machines is reliant upon a dual key and password system from a Lottery drawing official and a legislative auditor. Prior to each drawing, the drawing method and machine are randomly selected.