Patent ID: 7116785
Filing Date: 2006-10-03
Classification: G11B,H04L

Abstract:
1. A data processing apparatus for executing reproduction of a contents data from a memory device or recording of a contents data into said memory device comprising: an enabling key block distribution key enciphering key enciphered by an enabling key block containing enciphered data of renewal keys on such paths for constituting a key tree structure comprising a variety of keys disposed in correspondence with roots, nodes, and leaves on such paths ranging from roots to leaves of said key tree structure comprising a plurality of devices, wherein said enabling key block also contains data of upper-rank key enciphered via lower-rank key; and said data processing apparatus further comprises key distribution approval data files containing header data consisting of link count key for designating the number of contents data that should be enciphered by enciphering keys acquirable based on said enabling key block distribution key enciphering key stored in said enabling key block, thereby said key distribution approval data files are stored in said memory device.