| 摘要 |
Security is secured according to the type of a license so that unnecessary processing load is reduced. A license accumulation control unit (102) and a license transfer control unit (103) identifies a usage-rule type (204) which indicates whether or not a license (200) includes a usage rule (205) which requires updating each time a content is used, and encrypts the license (200) by using different encrypting methods depending on whether or not the usage rule (205) is included in the license (200). The license accumulation control unit (102) encrypts a content key: with a domain key when the license 200 does not include the usage rule (205); and with a license management device unique key, when the usage rule (205) is included, and accumulates the encrypted key in a license accumulation unit (110). The license transfer control unit (103), when the license (200) does not include the usage rule (205), reads the license (200) from the license accumulation unit (110) and transfers the license (200) with encryption maintained by using a license transfer unit (transfer method B) (105). |
