| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the total loads when a scramble key for decrypting encrypted content is generated after it is determined that a license is valid. <P>SOLUTION: The copyright protection device includes: a CPU 101 which executes an application 103; and a processor 111 which executes an application 113. The application 103 executes processing for storing license data including expiration date data and a work key which are acquired from a server 12 into a nonvolatile memory 130, and processing for transmitting time data acquired from the server 12 to the application 113. The application 113 executes processing for receiving a stream including the encrypted content and control data from a server 11, and processing for decrypting an encrypted scramble key using the work key when it is determined that the license is valid based on the present time calculated on the basis of the time data, and the expiration date data when the control data is received. <P>COPYRIGHT: (C)2011,JPO&INPIT |
