Patent attributes
A communication system is provided that allows communication between a vehicle and a server device. This communication system includes: the server device; a first arithmetic processing device installed in the vehicle; and a second arithmetic processing device that is a secure element and is installed in the vehicle. The second arithmetic processing device includes: a vehicle key storage unit that stores a first key and a second key; a vehicle authentication processing unit that performs authentication with the server device using the first key; and a vehicle key transmission/reception unit that transmits or receives a third key to or from the server device by encryption communication which uses the second key. The first arithmetic processing device includes a vehicle communication unit that performs encryption communication with the server device using the third key.