| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide the content reproducing device and the content distributing device for securing higher security. <P>SOLUTION: The content reproducing device obtains a plurality pieces of encrypted key information, where key information for decrypting the encrypted content data is encrypted, using encrypted content data, first current time information indicative of the current time for an external device, and a plurality pieces of mutually different time information. The device synchronizes second current time information indicative of the current time for the device body with the first current time information. If encrypted key information encrypted by time information corresponding to the second current time information exists among the plurality of encrypted key information, the device utilizes key information generated by decryption of the encrypted key information using the second current time information and decrypts the encrypted content data. Among the plurality pieces of encrypted key information, the device nullifies encrypted key information corresponding to time information indicative of a time prior to the current time indicated by the second current time information. <P>COPYRIGHT: (C)2010,JPO&INPIT |
