Patent ID: 8151357
Filing Date: 2012-04-03
Classification: G06F,G11B,H04L,H04N

Abstract:
1. An information recording medium manufacturing method, comprising: determining an encryption mode of each sector of a plurality of sectors, each sector serving as an encrypt processing unit for content to be recorded on an information recording medium, the determining step including determining whether each sector is a segment portion or a non-segment portion on the basis of an auxiliary file including determination information indicating whether each sector is data of the segment portion or data of the non-segment portion, each segment portion being defined as content encrypted based on a cryptographic key determined from a segment number and a variation number stored in the auxiliary file, and each non-segment portion being defined as content encrypted based on a unit identifier of the sector stored in the auxiliary file; determining, for each sector determined to be the data of the non-segment portion, a corresponding unit cryptographic key, based on the unit identifier of the sector recorded in the auxiliary file, wherein the corresponding unit cryptographic key is different depending on the unit identifier recorded in the auxiliary file, each unit cryptographic key being stored in a corresponding unit key file; generating first encrypted data using one of a plurality of predetermined cryptographic keys for each sector determined in the determining step to be the segment portion forming the content; generating second encrypted data by using the corresponding unit cryptographic key for each sector determined in the determining step to be the non-segment portion, the non-segment portion being different from the segment portion; and recording the first encrypted data generated for each segment portion and the second encrypted data generated for each non-segment portion on the information recording medium, wherein, in determining the encryption mode, a cryptographic key for each sector is determined, and if the sector is determined to be the segment portion forming the content, the cryptographic key is determined based on the segment number and the variation number associated with the sector and stored in the auxiliary file, and if the sector is determined to be the non-segment portion, the determined corresponding unit cryptographic key is used for the sector, and in generating the first encrypted data for the segment portion and the second encrypted data for the non-segment portion, the encrypted data is generated by using the determined cryptographic key.