Patent ID: 8127148
Filing Date: 2012-02-28
Classification: G11B,H04N

Abstract:
1. An information recording device for recording information on a recording medium, comprising: a secret-information decoding device adapted to read coded secret information stored on the recording medium by executing a process of reading that is different from a process of reading content data stored on the recording medium, the secret-information decoding device adapted to read the coded secret information comprising devices adapted to: read a digital playback signal comprising the coded secret information stored on the recording medium; generate a series of data strings as M-series signals comprising randomly changing logical values; and execute an arithmetic operation formed by exclusive OR circuits on the coded secret information and the M-series signals; wherein the coded secret information is decoded based on results of the arithmetic operation; and a cryptosystem comprising devices adapted to: generate a content-encryption key using a hash function and, as key-generating data, the decoded secret information; and execute, based on the content-encryption key, encryption processing on information to be recorded on the recording medium.