Abstract: The invention relates to a locking mechanism (1) for electromechanical protection of the hydraulic circuit of mechanically driven vessels/boats and vehicles, mostly trucks, but also private cars can be equipped with it, in which the steering gear and/or braking system can be blocked, in which a core cylinder (13) of the roughly 3/2-valve constructed locking mechanism (1) is operated by electronic control, in which in the driving position the mentioned core cylinder (13) is locked or blocked, in which the locking mechanism with accompanying electronic control (9) is mounted in a closed steel housing underneath the bonnet, which is also secured by the system and in which also an encoder unit (4) for further protection is provided, through which an optimally secure locking mechanism (1) against theft is created.