Patent ID: 7770795

Claim:
An information processing apparatus for recording information on an information recording medium, the information processing apparatus comprising: a content cryptographic processor configured to generate encrypted content by executing encryption using a unit key associated with a content management unit that serves as a unit for controlling usage of content; a unit-key-file processor configured to: (a) generate a unit key file storing the unit key; and (b) encrypt the unit key file or constituent data of the unit key file using an encryption key that is generated using a seed whose value is updated in accordance with a change in constituent data of unit keys included in the unit key file; and a data recorder configured to record the content management unit including the encrypted content as constituent data and the unit key file on the information recording medium according to a predetermined data recording format, wherein the data recorder is configured to: (a) change a writing location on the information recording medium in accordance with the number of times of writing of or the number of times of access to the unit key file when writing the unit key file; and (b) delete at least a part of data written to a location before changing the writing location.