ON-BOARD COMMUNICATION DEVICE, ON-BOARD COMMUNICATION SYSTEM, AND SPECIFIC PROCESSING PROHIBITION METHOD FOR A VEHICLE

An on-board communication device, an on-board communication system, and a specific processing prohibition method for a vehicle, in which a specific service can be prevented from being provided without limitation is disclosed. The on-board communication system can perform update processing of a relay processing program for a gateway using a wireless communication path through a wireless communication device or a communication path through a communication cable connected to a connector unit. When receiving an authentication request through either of the two communication paths, the gateway performs authentication processing, and if the authentication processing was successful, the gateway receives an update relay processing program through this communication path, and performs update processing by overwriting a stored relay processing program. At this time, the gateway prohibits update processing through any communication path other than the communication path through which the authentication processing was performed.