US 2006/0069650 A1 · Device and method for reproducing encrypted contents

Abstract

The present invention provides a technique for improving the convenience of the user while protecting the copyright of contents. A device receives contents usage right information from a storage device, and decrypts encrypted contents data using a contents key contained in the contents usage right information thus received. At this time, the device stores status information which indicates the use state of the contents usage right information. Furthermore, the device measures elapsed time for decryption of the encrypted contents data using the contents key, or elapsed time for reproduction of the contents data decrypted using the contents key. The device determines whether or not the contents usage right information has been used, based upon the elapsed time thus measured. Then, the device updates the status information stored in a log storage device, based upon the determination result.

Claims23

Dependent claims

A content reproducing device for decrypting and reproducing encrypted content data using content usage right information containing a content key for decrypting the encrypted content data stored in a storage device, said content reproducing device comprising:

an interface controlling transmission/reception of data to/from said storage device;
a content decryption unit for decrypting said encrypted content data using the content key contained in said content usage right information;
a content key output unit for receiving said content usage right information from said storage device, and outputting said content key contained in said content usage right information to said content decryption unit;
a log storage unit for storing status information which indicates a use state of said content usage right information;
and
a determining unit for acquiring elapsed time for which said encrypted content data has been decrypted by said content decryption unit using said content key, or elapsed time for which said content data, which has been decrypted by said content decryption unit using said content key, has been reproduced, determining whether or not said content key has been used based upon said elapsed time thus acquired, and updating status information stored in said log storage unit based upon determination results.

3 more elements

Dependencies are inferred from the claim text.

Device and method for reproducing encrypted contents

Life of this patent

Device and method for reproducing encrypted contents

Life of this patent

Abstract

Claims23