| 摘要 |
Improvement of the security of communication is facilitated. A server (101) receives from an on-vehicle device (102), encrypted data (121) obtained by encrypting ECU information (120) using key information (111-1#C), and identification information (112-1#C). Thereafter, the server (101) determines from the identification information (112-1#C), whether identification information of a next key to be used after identification information (112-1) is stored. The server (101) determines that the identification information of the next key to be used after the identification information (112-1) is not stored, and obtains key information (111-2#S) and identification information (112-2#S) to identify key information (111-2) as the next key. The server (101) encrypts the key information (111-2#S) and the identification information (112-2#S) using key information (111-1#S), and transmits encrypted data (122) and identification information (112-1#S) to the on-vehicle device (102). |
