DATA PROCESSING METHOD, PROGRAM THEREOF, APPARATUS THEREOF, AND RECEIVER

摘要

PROBLEM TO BE SOLVED: To provide a data processing method capable of decreasing a data amount of data stored in a revoked receiver more than that of a prior art in order to properly revoke the receiver among a plurality of receivers for carrying out encryption communication on the basis of key data. SOLUTION: A key management apparatus 3 particularizes a single set or a plurality of sets S(k, m) whose elements are only unrevoked receivers among receivers assigned to M sets of clusters CLUS(m) as to each of M-sets of the clusters CLUS(m) to which the receivers are assigned (ST23). Then the key management apparatus 3 transmits instruction data for instructing data to acquire the key data corresponding to the sets S(k, m) to the receivers (ST28). COPYRIGHT: (C)2005,JPO&NCIPI