| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem in a conventional technique in which there has been the risk of key leakage by an illegal set manufacturer, etc.SOLUTION: When a key is mounted, first encryption key data is received, the first encryption key data is decrypted by using a first encryption key, and first decryption key data is generated. A second encryption key is generated based on a second ID. Decryption key data is encrypted by using the second encryption key, and second encryption key data is generated and written in a storage unit. When the mounted key is utilized, the second encryption key data is read from the storage unit, the second encryption key is generated based on the second ID, the second encryption key data is decrypted by using the second encryption key, and second decryption key data is generated. |
