| 摘要 |
In order to enable encrypted communications using a pre-shared key, between a novel communications device and a partner communications device without any partner communications device operation, a management device (C1) as a communications device first generates a backup pre-shared key that is the same as a pre-shared key PSK (C1-D1) that had been shared with the partner communications device, sends same to a backup server (4), and causes the backup server to hold same. Then, a management device (C2) used as a novel communications device as an alternative to the management device (C1) receives the backup pre-shared key PSK (C1-D1) from the backup server (4), uses this pre-shared key, encrypts a public key electronic certificate for the management device (C2), and sends same to the partner communications device. |
