Abstract: A key distribution system distributes key data for using content to a second encryption device that has been legitimately outsourced processing by a first encryption device. The first encryption device acquires permission information indicating that the first encryption device has permission to use the content, generates certification information by making an irreversible alteration the to permission information, and transmits the permission information and the certification information to the second encryption device. The second encryption device receives the permission information and the certification information, sends them to a key distribution device, and acquires the key data from the key distribution device. The key distribution device receives the permission information and the certification information, judges whether or not the certification information was generated by the by the first encryption device, and if judging in the affirmative, transmits the key data to the second encryption device.

Abstract: A reservation changing system provides diverse services. A memory card obtains, via a mobile telephone, a distance from a present location to a boarding station for a train for which a reservation has been made, and judges whether to perform a train reservation change search depending on the relationship between the obtained distance and a time remaining until a departure time of the train. When it is judged that a reservation change search is to be performed, the memory card obtains an expected arrival time at the station from a timetable server apparatus, compares the obtained expected arrival time with the departure time, and when a time margin between the two times is insufficient, the memory card instructs a reservation center apparatus, via the mobile telephone, to change the reservation, and receives and stores reservation information.

Abstract: The recorder/reproducer, when moving a first content data, writes a second content data, which is obtained by re-coding the first content data recorded in a first recording medium, into a second recording medium instead of the first content data, writes one or more first partial information extracted from the first content data into the second recording medium, and makes the first content data irreproducible, using one or more first invalidated partial information having one-to-one correspondence with the extracted one or more first partial information. When restoring the first content data, it makes the irreproducible first content data reproducible, using the one or more first partial information recorded in the second recording medium.

Abstract: An authentication communication system is capable of storing information relating to revoked devices in less area than is conventionally required. A computer unit stores in advance revocation information that indicates at least one revoked apparatus, and when authenticating a driver unit judges, based on the revocation information, whether or not the driver unit is revoked. The computer unit prohibits communication with the driver unit when the driver unit is judged to be revoked, and communicates with the driver unit when the driver unit is judged not to be revoked.

Abstract: A recording device for recording one or more of a plurality of subcontents recorded on a first recording medium, onto a second recording medium, the first recording medium having further recorded thereon digest values of the subcontents, and a medium signature generated based on the digest values of the subcontents, the plurality of subcontents constituting one content, the recording device comprising: a subcontent acquisition unit operable to select and acquire one or more of subcontents permitted to be copied; an excluded digest value acquisition unit operable to acquire excluded digest values from the first recording medium, the excluded digest values being digest values of nonselected subcontents; a signature acquisition unit operable to acquire the medium signature from the first recording medium; and a write unit operable to write, onto the second recording medium, (i) the one or more selected subcontents, (ii) the excluded digest values, and (iii) the medium signature.

Abstract: To provide a content playback device that can use content appropriately by avoiding output of content not permitted to be used according to contract information. A playback control unit 102 extracts a content name from playback control information in a playback path information table 210, and inquires of a rights management unit 108 whether content identified by the extracted content name is playable or not. If the content is judged as being unplayable, the playback control unit 102 extracts an alternative playback number from the playback control information, and extracts a content name from playback control information whose playback number matches the alternative playback number. The playback control unit 102 then instructs a decryption unit 103 and a playback unit 107 to decrypt and play back encrypted content identified by the extracted content name.

Abstract: A content playback apparatus (digital watermark detection apparatus) comprises: a detection unit operable to detect a digital watermark from audio data having a plurality of blocks, the audio data being contained in a content which is to be played back along a playback time-line; a detected block storage unit for storing therein information indicating a block in which the digital watermark has been detected by the detection unit; and a playback control unit operable to play back all data contained in the content other than audio data corresponding to the block indicated by the information stored in the detected block storage unit. This makes it possible, even when audio data containing copyright information is inadvertently recorded on a camcorder, to prevent the audio data containing the copyright information from being played back, thereby enabling users to view the content without the influence of playback control.

Abstract: A memory card 10 inserted in a terminal device 20 establishes a SAC with each of a content server 1, a content server 2, a settlement server 1 and a settlement server 2, using an application program corresponding to the server, to securely receive and transmit data. The memory card 10 acquires a unique private key and a unique public key for each application program, and establishes a SAC with each server using the acquired private key and public key.

Abstract: To provide a content playback device that can use content appropriately by avoiding output of content not permitted to be used according to contract information. A playback control unit 102 extracts a content name from playback control information in a playback path information table 210, and inquires of a rights management unit 108 whether content identified by the extracted content name is playable or not. If the content is judged as being unplayable, the playback control unit 102 extracts an alternative playback number from the playback control information, and extracts a content name from playback control information whose playback number matches the alternative playback number. The playback control unit 102 then instructs a decryption unit 103 and a playback unit 107 to decrypt and play back encrypted content identified by the extracted content name.

Abstract: An executing device conducts playback of contents. The executing device is equipped with a highly efficient processor and reduces the processing load involved in verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on a DVD. In addition, the executing device is capable of improving the accuracy of detecting unauthorized contents by randomly selecting a predetermined number of encrypted units every time the verification is performed.

Abstract: It is an object of the present invention to provide a universal drive capable of recording and reproducing high-image quality contents on and from various media, such as BD, HD-DVD, DVD and others according to the AACS. The drive (10) is connected to a host apparatus, and which reads from and writes onto a media M, which includes: a readout unit (11) which reads and writes information from and onto the recording medium; a media type identifying unit (12) which identifies a type of the recording medium based on the information read from the recording medium by the readout unit (11); and a data analysis unit (13) and an authentication unit (14) which performs an operation for copyright protection associated with a result of the identification by the media type identifying unit (12).

Abstract: The object of the present invention is to provide a reproduction apparatus that is capable of preventing personal information of users from being transmitted to an external apparatus that is under management of a malicious person. The reproduction apparatus uses a revocation list and a valid-content list in combination in order to prevent transmission of personal information of users. It is possible to prevent transmission of personal information by revoking certificates to be revoked because of being exposed or hacked at a certain timing, by listing them in the revocation list. Meanwhile, it is possible to allow use of contents that have been manufactured before the exposure, by listing them in the valid-content list. Accordingly, it is possible to realize both the security and the user convenience at the same time.

Abstract: An encrypted content playback apparatus and a playback method are suitable for content playback from a recording medium having stored thereon both content that is subject to conventional copy protection and content to which DRAM is applied. The recording medium stores information indicating, for each content, whether the content is content subject to conventional copy protection or content to which DRAM is applied. Based on this information, the playback apparatus determines the key to use to decrypt the content.

Abstract: If playback devices are prohibited from playing back contents recorded in R media, there occurs a problem that it takes more time to manufacture commercial ROM media. Conversely, if playback devices are permitted to play back contents recorded in R media, there occurs a problem that copyrights might be infringed. In view of these, the aim of the present invention is to provide a content protection data processing system and a playback device capable of determining whether to permit playback of a content recorded in a recording medium, based on a medium type of the recording medium and a signature type of a signature attached to a program, and switching a procedure relating to a digital signature for each signature type of the digital signature. This enables both the protection of the copyright of the content and the efficient manufacturing of commercial ROM media.

Abstract: Disclosed is a digital work protection system enabling a content distributor to flexibly define usage patterns of content permitted for users. The system is composed of a recording device and a playback device. The recording device acquires a digital work, range information showing a permission range within which the digital work is permitted to be used, and a subrange key for each subrange, generates an encryption key using all the acquired subrange keys, encrypts the digital work based on the encryption key to generate encryption information, and writes the encryption information and the range information to a recording medium. The playback device reads the range information and the encrypted information from the recording medium, acquires a subrange key for each subrange, generates a decryption key using all the acquired subrange keys, decrypts the encrypted information based on the decryption key to generate a digital work, and plays the digital work.

Abstract: If playback devices are prohibited from playing back contents recorded in R media, there occurs a problem that it takes more time to manufacture commercial ROM media. Conversely, if playback devices are permitted to play back contents recorded in R media, there occurs a problem that copyrights might be infringed. In view of these, the aim of the present invention is to provide a content protection data processing system and a playback device capable of determine whether to permit playback of a content recorded in a recording medium, based on a medium type of the recording medium and a signature type of a signature attached to a program. This enables both the protection of the copyright of the content and the efficient manufacturing of commercial ROM media.

Abstract: A data protection system is provided that reduces, to a degree, the amount of encrypted data that is distributed to a plurality of terminals. In the data protection system a terminal whose decryption keys are exposed by a dishonest party is made to be unable to decrypt the data correctly, while other terminals are able to decrypt the data correctly. The data protection system includes a plurality of terminals, and an encryption device that encrypts distribution data distributed to each terminal. Each terminal is corresponded with one node on a lowest level of a 4-ary tree structure or the like having a plurality of hierarchies.

Abstract: The present invention provides an information embedding apparatus that is capable of preventing playback stop of a content that has been shot without intention of misuse. The information embedding apparatus comprises: an acquisition unit operable to acquire the content that is played back along the playback time-line; a watermark generating unit operable to generate the watermarks such that values held by the watermarks vary according to a first rule, the first rule showing that the values should vary according to a sequential order on the playback time-line; and an embedding unit operable to embed two or more of the watermarks into the content while keeping the sequential order.

Abstract: A device that ensures that one device acquires and updates a list used for judging whether the other device in communication is valid or invalid, in a device authentication system. When a list H stored in a personal computer 200 is old, the personal computer 200 acquires a latest version of the list H and a latest version of a list D from outside an internal network, updates the list H stored therein to the latest version, and updates the list D stored therein to the latest version.

Abstract: In an information input/output system, a user device inputs and outputs information to and from external sources including a key management device. The system includes the key management device that securely outputs invalid-device information specifying an invalid device unit that has been made invalid for use, and the user device that includes an input/output unit and a host unit. Via the input/output unit, input and output of information is enabled between the host unit and the external sources. The host unit securely receives, via the input/output unit, the invalid-device information outputted by the key management device and judges whether or not the input/output unit is an invalid device unit by referring to the received invalid-device information. When judging, that the input/output unit is an invalid device, the host unit thereafter prohibits input and output via the input/output unit.