| 摘要 |
In reproduction of information, a decoding program is reproduced from an information recording medium on which information is enciphered and recorded, and an encryption key and the decoding program, which are used to decode the information, are recorded as well. At least one of the encryption key and the decoding program is erased in accordance with an instruction from the decoding program. It is confirmed whether at least one of the encryption key and the decoding program has been erased. Activation of the decoding program is terminated when it is confirmed that at least one of the encryption key and the decoding program has been erased.
|
