METHOD FOR GENERATING CONTROL WORDS ABOUT DIGITAL CONTENTS WHICH ARE PROTECTED IN DIGITAL RIGHTS MANAGEMENT AND A DEVICE THEREOF

摘要

PURPOSE: A method for generating control words about digital contents which are protected in digital rights management and a device thereof are provided to reduce calculation costs and improve bandwidth efficiency by sharing a part of contents which are protected.;CONSTITUTION: A device generates the n number of control words for the encryption and decryption of the n number of successive units of content items. The device obtains a first primary key and a secondary key. The device generates a first ordered set of the n number of sub keys by repetitively applying a first one-way function to the primary key and a second ordered set of the n number of the sub keys by repetitively applying a second one-way function to the secondary key. The device generates the n number of the control words by repetitively using an join operation in order to the control words from the sub keys from the first ordered set of the n number of the sub keys and the second ordered set of the n number of the sub keys.;COPYRIGHT KIPO 2012