Vehicle communication system

A vehicle communication system comprising:

• a transfer unit including
• a control circuit that includes an internal controller, is incorporated in a vehicle, is connected to a device, and performs a transfer process of transferring information to the device, and
• an external controller that is provided outside the control circuit, is connected to the control circuit, has higher information processing capability than the internal controller, is able to perform a transfer order process of ordering to perform the transfer process, and when performing the transfer order process, is able to perform a security process of securing security of the information to be transferred, wherein
• the internal controller monitors operation of the external controller, and when the external controller is abnormal, the internal controller performs the transfer order process instead of the external controller;
• and
• a plurality of the transfer units, wherein
• the transfer units include a first transfer unit and a second transfer unit that transfers information transmitted from the first transfer unit,
• when the external controller of the first transfer unit is normal, the first transfer unit transmits, to the second transfer unit, security secured information for which the external controller of the first transfer unit has performed the security process so that the security is secured, and the second transfer unit transfers the security secured information transmitted from the first transfer unit without performing the security process, and
• when the external controller of the first transfer unit is abnormal, the first transfer unit transmits, to the second transfer unit, security unsecured information for which the security process has not been performed, and the second transfer unit causes the external controller of the second transfer unit to perform the security process for the security unsecured information transmitted from the first transfer unit and transfers the information.