Data reproduction apparatus capable of safely controlling reproduction time of encrypted content data and data reproduction circuit and data recording apparatus used for the same
    7.
    发明授权
    Data reproduction apparatus capable of safely controlling reproduction time of encrypted content data and data reproduction circuit and data recording apparatus used for the same 有权
    能够安全地控制加密的内容数据的再现时间的数据再现装置和用于其的数据再现电路和数据记录装置

    公开(公告)号:US07428307B2

    公开(公告)日:2008-09-23

    申请号:US10482681

    申请日:2002-06-26

    IPC分类号: H04L9/00

    摘要: A decryption processing unit decrypts encrypted content data using a license key Kc. When an elapsed time after reception of the license key (Kc) does not exceed a hold time at a time of the license key (Kc) included in reproduction control information (ACp), reproduction of encrypted content data continues. When the elapsed time exceeds the hold time at a time, the license key (Kc) is discarded, and a reproduction control unit again obtains a license key (Kc) from a memory card. Discarding and reobtaining license key (Kc) continues until an allowable output count of license key (Kc) from the memory card becomes zero. As a result, a reproduction time of encrypted content data can be controlled safely.

    摘要翻译: 解密处理单元使用许可证密钥Kc对加密的内容数据进行解密。 当接收到许可证密钥(Kc)之后的经过时间不超过包含在再现控制信息(ACp)中的许可证密钥(Kc)时的保持时间时,继续加密内容数据的再现。 当经过时间超过一次的保持时间时,许可证密钥(Kc)被丢弃,并且再现控制单元再次从存储卡获得许可证密钥(Kc)。 丢弃并重新获得许可证密钥(Kc),直到来自存储卡的许可证密钥(Kc)的允许输出计数变为零。 结果,可以安全地控制加密的内容数据的再现时间。