| 摘要 |
The objective of the invention is to improve the safety of communications. A server (101) receives, from a vehicle-mounted device (102), both encrypted data (121), which has been obtained by using key information (111-1#C) to encrypt ECU information (120), and identification information (112-1#C). After the reception, the server (101) determines, from the identification information (112-1#C), whether the identification information of a key, which is to be used next to the identification information (112-1), has been stored. Having determined that the identification information of the key to be used next to the identification information (112-1) has not been stored, the server (101) acquires, as the next key, identification information (112-2#S) used for identifying key information (111-2#S) and key information (111-2). The server (101) then uses key information (111-1#S) to encrypt the key information (111-2#S) and the identification information (112-2#S) and transmits encrypted data (122) and identification information (112-1#S) to the vehicle-mounted device (102). |
