APPARATUS AND METHOD FOR DETERMINING REVOCATION KEY, AND APPARATUS AND METHOD FOR DECRYPTING CONTENTS USING THE SAME

摘要

A revocation key determining method for content protection. The revocation key determining method includes: identifying at least one of a plurality of groups on the basis of a structure in which groups, each consisting of nodes to which key sets for content protection are respectively assigned, are hierarchically arranged in a tree form; and detecting whether nodes belonging to the group are respectively revoked.