| 摘要 |
PROBLEM TO BE SOLVED: To reduce the frequency required for a mobile apparatus and an on-vehicle device to communicate with a key issue device, and to achieve the security of safety by the update of a key for cipher communication with the reduction of a resource required to store the key.SOLUTION: In a vehicle communication system in which a mobile apparatus 7 carried by a user of a vehicle and an on-vehicle device 5 store a key issued by a key issue device 9 to perform cipher communication using the stored key, the key and validity information on the key are issued from the key issue device 9 to the on-vehicle device 5. When determining that a validity period indicated by the validity information arrives, the on-vehicle device 5 transmits a key update request to the key issue device 9. When receiving the key update request (S160: YES), the key issue device 9 issues a new key to the mobile apparatus 7 and also issues the new key and validity information on the key to the on-vehicle device 5 (S130-S150).SELECTED DRAWING: Figure 2 |
