Information recording medium, information recording device, information reproduction device, information delivery device, their methods, their programs, and recording medium recording programs thereon

摘要

Contents encrypted by content encryption keys AE_R1, AE_R34 and content decryption keys AD_R1, AD_R34 encrypted by encryption keys BE₄, BE₆, BE₇ are recorded on recording media 301, 302. The encryption keys BE₄, BE₆, BE₇ differ among playback regions 1 to 4 preset to control the permission and inhibition of content playback. Content playback regions can be limited by using only the encryption keys of regions where playback is permitted. Even if a key is leaked out, the other playback regions are not affected because the encryption keys differ among playback regions and therefore the copyright protection function is increased.