VERFAHREN UND GERÄT ZUM KONTROLIEREN DES VERTEILENS UND DER BENUTZUNG VON DIGITALWERKEN

摘要

Disclosed is a method and device for controlling distribution and use of a digital work stored together with an attached usage right information on a record carrier. The attached usage right information is encrypted or verified by using a hidden information which is changed at every change of said usage right information. The hidden information may be an encryption key used for encrypting the usage right information, or a checksum of a data block containing the usage right information. Thus, a 'copy and restore attack' is not successful, since it will lead to a mismatch between the hidden information and the restored usage right information.