Patent ID: 7428307
Filing Date: 2008-09-23
Classification: G06F,G11B

Abstract:
1. A data reproduction apparatus decrypting and reproducing encrypted content data of which reproduction is defined by first reproduction control information that specifies an allowable retrieval count of a license key for decrypting encrypted content data from a data recording apparatus for reproduction and second reproduction control information that specifies an allowable hold time of the retrieved license key, comprising: an interface controlling data transfer from/to said data recording apparatus; content reproduction means decrypting and reproducing said encrypted content data using said license key; key operation means inputting an instruction; control means and a timer unit notifying said control means of passage of time, wherein said control means obtains said encrypted content data, said license key and said second reproduction control information from said data recording apparatus via said interface in response to a reproduction request for said encrypted content data that is input via said key operation means, applies the obtained license key and encrypted content data to said content reproduction means, discards the license key applied to said content reproduction means when an elapsed time after application of said license key to said content reproduction means reaches the allowable hold time specified by said second reproduction control information, and obtains again said license key, which is not the discarded license key, and said second reproduction control information from said data recording apparatus for application to said content reproduction means at a timing that allows said encrypted content data to be reproduced continuously, upon starting to use said license key, said control means performs on said timer unit a timer setting of the allowable hold time specified by said second reproduction control information, said timer unit notifies said control means when said allowable hold time has expired after said timer setting, and said control means obtains said encrypted content data per block from said data recording apparatus for application to said content reproduction means, and determines whether or not said elapsed time reaches said allowable hold time every time the encrypted content data included in one block is applied to said content reproduction means.