Patent ID: 7146507
Filing Date: 2006-12-05
Classification: G06F,G11B,H04N

Abstract:
1. An information recording apparatus comprising: first means for dividing first information to be recorded into equal-size information pieces; second means for assigning serial numbers to the information pieces respectively which are generated by the first means; third means for generating a secret function from a base number and a variable number varying for each of the information pieces, the base number being common to content data managed by one licence; fourth means for generating an encryption key according to the secret function generated by the third means, the encryption key being updated for each of the information pieces; fifth means for encrypting the first information on a block-by-block basis with the encryption key generated by the fourth means to get encryption-resultant information for every predetermined minimum information unit smaller than the sizes of the information pieces; sixth means for recording the encryption-resultant information generated by the fifth means on a recording medium; seventh means for determining logical addresses of heads of portions of the recording medium which are recorded with portions of the encryption-resultant information corresponding to the respective information pieces; eighth means for determining a correspondence relation between the logical addresses determined by the seventh means and the assigned serial numbers, and generating second information representing the determined correspondence relation; and ninth means for recording the second information on the recording medium.