Patent attributes
A communication relay device that is situated between a corresponding communication node and a bus in a communication network in which a plurality of communication nodes mutually perform a data communication through the bus. A storage configured to store therein pieces of identification information that are likely to be included in data transmitted by the corresponding communication node. A processor configured to perform first authentication processing between the communication relay device and a management device that is connected to the bus, and to perform second authentication processing according to a result of comparing identification information included in data transmitted by the corresponding communication node with the pieces of identification information stored in the storage. A transceiver configured to report, to the management device, a result of the second authentication processing when the first authentication processing has been successful.