Patent ID: 8073143

Claim:
An information processing device comprising: a processor; a recording medium interface configured to read data from an information recording medium which stores data in increments of: (a) a first content management unit which includes first encrypted data that is encrypted by a first unit key that is set as a first encryption key; and (b) a second content management unit which includes second encrypted data that is encrypted by a second unit key that is set as a second, different encryption key; and a memory device storing instructions which when executed by the processor, cause the processor to: (a) record new data which is either generated or obtained applying information obtained from the information recording medium; (b) obtain at least one of: (i) the first unit key, the first unit key corresponding to the first content management unit to which the obtained information belongs; and (ii) a third, different unit key which corresponds to a third, different content management unit to which the obtained information does not belong; (c) in response to the first unit key being obtained: (i) encrypt the new data applying the obtained first unit key; and (ii) execute recording processing with said encrypted new data as data configuring the first content management unit; and (d) in response to the third, different unit key being obtained: (i) encrypt the new data applying the obtained third, different unit key; and (ii) execute recording processing with the encrypted new data as data configuring the third, different content management unit.