Patent ID: 7620820
Filing Date: 2009-11-17
Classification: G11B

Abstract:
1. A data processing method comprising: generating reference information including invalid device key data corresponding to at least one invalid apparatus of a plurality of apparatuses, valid device key data corresponding to at least one valid apparatus of the plurality of apparatuses and data encrypted from contents key data, by encrypting said contents key data using said device key data associated with the at least one valid apparatus of said plurality of apparatuses for which recording or reproduction is allowed; supplying the generated reference information along with said device key data to said plurality of apparatuses; said plurality of apparatuses decrypting said contents key data from the supplied reference information, using said device key data proper to said plurality of apparatuses; encrypting or decrypting contents data using the decrypted contents key data; wherein the device key data supplied and the reference information supplied are stored in a memory of each of said plurality of apparatuses; and wherein data used for verifying whether or not the reference information supplied is valid is pre-stored in said plurality of apparatuses plural apparatus and wherein the validity of the reference information supplied is verified based on said verifying data.