| 摘要 |
There is provided the present invention to prevent illegal copying of recorded information and enable flexible management of contents, and further facilitate improvement of copy protection technology and the like. A key obtaining module ( 2 ) is recorded on a read-only information recording medium ( 1 ) to which a copy protection technology is applied. A reproducing module ( 3 ) safely obtains a media key unique to the key obtaining module ( 2 ) from the key obtaining module ( 2 ), generates a content key from the media key, and decrypts an encrypted content ( 4 ) using the content key and reproduces the content. In this case, while the key obtaining module ( 2 ) needs to be present on the information recording medium ( 1 ), the reproducing module ( 3 ) and the encrypted content ( 4 ) do not need to be present on the information recording medium ( 1 ) and may be present outside the information recording medium ( 1 ). |
