A method according to one embodiment includes the operations of configuring a host processor to receive a message filtering rule, the host processor associated with a vehicle; configuring a bus controller to verify authenticity of the message filtering rule, wherein the bus controller is programmed through an interface, the interface inaccessible from the host processor; filtering messages from the host processor using the verified message filtering rule, wherein the filtering is performed by the bus controller; and transmitting the filtered messages from the bus controller over a bus to one or more electronic control units (ECUs), the ECUs communicatively coupled to the bus.