Method of updating fraud detection rules for detecting malicious frames, fraud detecting electronic control unit, and on-board network system

A fraud detecting electronic controller connected to one or more networks used for communication by a plurality of electronic controllers, comprising:

• a processor, and
• a memory having a computer program stored thereon, the computer program causing the processor to execute operations, including
• storing fraud detection rules;
• determining whether or not a message transmitted on the network connected to the fraud detecting electronic controller conforms to the rules based on the fraud detection rules;
• querying an external device whether or not there is delivery data for updating the fraud detection rules;
• when there is the delivery data for updating the fraud detection rules, receiving the delivery data including updated fraud detection rules and network type information indicating one of a plurality of network types to which the updated fraud detection rules are to be applied;
• determining whether or not a vehicle in which an on-board network system is installed is running, the on-board network system including the plurality of controllers;
• when the vehicle is determined to be running, additionally determining whether or not the network type information indicates a drive network that is connected to an electronic controller related to a travel of the vehicle;
• (i) when the network type information indicates the drive network, not conducting an update process with the updated fraud detection rules;
• and
• (ii) when the network type information does not indicate the drive network, updating the fraud detection rules to the updated fraud detection rules.

An on-board network system, comprising:

• a plurality of electronic controllers configured to exchange messages by communication over one or more networks;
• and
• a fraud detecting electronic controller configured to connect to the one or more networks,
• wherein the fraud detecting electronic controller determines whether or not a message transmitted on the one or more networks connected to the fraud detecting electronic controller conforms to the rules based on fraud detection rules,
• one of the electronic controllers queries an external device whether or not there is delivery data for updating the fraud detection rules, receives, from an external device external to the on-board network system, the delivery data including updated fraud detection rules and network type information indicating one of a plurality of network types to which the updated fraud detection rules are to be applied when there is the delivery data for updating the fraud detection rules, and transmits the updated fraud detection rules over the one or more networks, and
• the fraud detecting electronic controller
• receives the updated fraud detection rules from the one or more networks,
• determines whether or not a vehicle in which the on-board network system is installed is running,
• when the vehicle is determined to be running, additionally determines whether or not the network type information indicates a drive network that is connected to an electronic controller related to the travel of the vehicle,
• (i) when the network type information indicates a drive network related to running, does not conduct an update process with the updated fraud detection rules, and
• (ii) when the network type information does not indicate a drive network related to running, updates the fraud detection rules to the updated fraud detection rules.