Patent ID: 7747532
Filing Date: 2010-06-29
Classification: G06F,G06Q

Abstract:
1. A content use management system, comprising: a license issuance apparatus for issuing a license corresponding to digital content, including license generation means for generating the license including at least content identification information for uniquely identifying the digital content, available-period-of-time information for defining a period of time within which the digital content can be used, and reference date/time information; and license issuance means for issuing the license; and a content playback apparatus for using the digital content with the license, including license acquisition means for acquiring the license; license storage means for storing the license; reference-date/time-information storage means for storing the reference date/time information; reference-date/time-information update means for updating the reference date/time information stored in the reference-date/time-information storage means with the reference date/time information included in the license based on whether the reference date/time information included in the license is newer than the reference date/time information stored in the reference-date/time-information storage means; system-date/time-information acquisition means for acquiring system date/time information in the content playback apparatus; validation means for determining validity of the system date/time information based on a comparison of the system date/time information with the reference date/time information stored in the reference-date/time-information storage means; and determination means for determining whether or not the digital content corresponding to the content identification information can be used according to the validity of the system date/time information and the available-period-of-time information.