Abstract: A plurality of first encrypted pieces is generated by encrypting the pieces with a first encryption key. The second encrypted piece is generated by encrypting at least one of the pieces with a second encryption key. The first encryption key and the second encryption key for encrypting the same piece are different from each other. A communication apparatus receives a first encrypted piece or a second encrypted piece from other communication apparatus for each piece, transmits a request message for requesting a decryption key for decrypting the encrypted piece to a key server, and receives the decryption key from the key server in response to the request message.

Abstract: According to one embodiment, an information storage medium comprises a content encrypted by a content encryption key; a content encryption key file encrypted by a first encryption key or third encryption key; an encryption key block from which a third encryption key prime providing a source of the first encryption key or third encryption key by being processed by using a second encryption key of a player; and a program configured to make the player calculate the third encryption key from the third encryption key prime. The content encryption key file comprises a flag indicating whether the key file is encrypted by the third encryption key or first encryption key.

Abstract: According to one embodiment, a recording apparatus includes a receiving section which receives a stream and address information indicating an encryption target region of the stream, and a recording section which records the stream on each sector of a recording medium and records management information on a sector header of the sector where data on the encryption target region is recorded.

Abstract: According to a data display method, data having a program unit and instruction data for the program unit multiplexed on bit stream data is received. The program unit is extracted from the received data and is stored in a memory. The instruction data is extracted from the received data, and the program unit or part thereof specified by the instruction data is read from the memory and is executed. Then, the bit stream data and the execution result are displayed. This ensures smooth synchronization of reproduction of a bit stream with execution of an associated program and efficient use of resources.

Abstract: A scheme for realizing communications through an external network such as telephone network from a contents processing device such as AV device or PC connected to a local network such as home network is disclosed. The contents processing device solicits a set up of connection to the server device through the telephone network, to a gateway device which is connected with both the home network and the telephone network. Then, the gateway device carries out a call set up with respect to a specified address on the telephone network, upon receiving the solicitation from the contents processing device, and transfers data transmitted from the contents processing device to a connection established by the call set up, and data arriving from the connection established by the call set up to the contents processing device.

Abstract: A content reproducing apparatus includes: a disc drive device that reproduces content recorded on a recording medium; a network controller that controls data transmission between an external server specified by the content reproduced by the disc drive device; a content protection encoder/decoder unit that: (1) encodes a request to be sent to the external server via a proxy server that decodes the request; and (2) decodes a response from the external server being transmitted in response to the request decoded by the proxy server, the response being encoded by the proxy server; and a controller that controls the network controller and the content protection decode/encoder unit.

Abstract: According to a data display method, data having a program unit and instruction data for the program unit multiplexed on bit stream data is received. The program unit is extracted from the received data and is stored in a memory. The instruction data is extracted from the received data, and the program unit or part thereof specified by the instruction data is read from the memory and is executed. Then, the bit stream data and the execution result are displayed. This ensures smooth synchronization of reproduction of a bit stream with execution of an associated program and efficient use of resources.

Abstract: The information reproduction device for reproducing contents information based on license information added to the contents information and required for reproducing the contents information, includes a determining section for determining whether encrypted contents information is the officially copied contents information or privately copied contents information based on the contents of the license information, and a reproduction section configured to reproduce the contents information determined as the privately copied contents information by the determining section under more severe restriction than the officially copied contents information. Thus, the contents copied by the proper route (officially copied contents) can be distributed in a more advantageous form than the contents copied without proper authorization.

Abstract: An information recording apparatus comprises an encryption section encrypting contents information and also a license condition referred to to limit use of the contents information and a decoding key for decoding the encrypted contents information to generate license information, and a recording section recording the encrypted contents information and the generated license information on a recording medium. An information reproducing apparatus comprises a decoder unit decoding the license information recorded on the recording medium using a second decoding key for decoding the license information and deciding on the basis of the license condition contained in the decoded license information whether the contents information can be used. If it is decided that the contents information can be used, the encrypted contents information recorded on the recording medium is decoded using the first decoding key contained in the decoded license information.

Abstract: Each embodiment of this invention implements step-by-step and empirical authentication of devices upon digital authentication among a plurality of devices. Each of a plurality of authentication devices of each embodiment can unidirectionally generate a hash value of a low experience rank from a hash value of a high experience rank, and receives a set of high experience rank and hash value in accordance with an experience. Upon receiving a certification request of the experience rank from another authentication device, the authentication device transmits a corresponding hash value to the authentication device as a request source. Upon sending a certification request of an experience rank to another authentication device, the authentication device verifies a hash value obtained from the other authentication device on the basis of a self hash value. In this way, the authentication devices authenticate each other's experience ranks.

Abstract: A device information generating device comprises a device key matrix storage unit configured to store a device key matrix in which device keys are arranged in a two dimensional manner, and a device key generating unit configured to select one of the device keys in each one dimensional array of the device key matrix according to each numeral of a device ID, wherein the selected device keys and the device ID are the device information.

Abstract: According to one embodiment, a playback apparatus includes a unit which determines whether a value of a pointer included in each of video object units read out of a storage media is larger than the total number of hash values in a content hash table stored in the storage media, a unit which computes a hash value of a video object unit selected at a given probability from among the video object units read out of the storage media and determines whether the computed hash value coincides with a hash value stored in a hash entry indicated by a pointer included in the selected video object unit, and a unit which stops playing back digital content when the value of the pointer is larger than the total number of hash values or when the computed hash value does not coincide with the hash value stored in the hash entry.

Abstract: The information reproduction device for reproducing contents information based on license information added to the contents information and required for reproducing the contents information, includes a determining section for determining whether encrypted contents information is the officially copied contents information or privately copied contents information based on the contents of the license information, and a reproduction section configured to reproduce the contents information determined as the privately copied contents information by the determining section under more severe restriction than the officially copied contents information. Thus, the contents copied by the proper route (officially copied contents) can be distributed in a more advantageous form than the contents copied without proper authorization.

Abstract: When the same object appearing in a moving picture is divided into a plurality of items of data (access units), search results using meta data is easily displayed. A meta data stream includes two or more access units AUs having an object_id for specifying whether or not objects designated by object region data in two access units AUs are semantically identical, and an object_subid for specifying whether or not the object region data in the two access units AUs are data on the same scene. From the meta data stream, one of a plurality of access units AUs is selected, the access units being determined to be the same objects by the object_id and being determined to be the same scene by the object_subid, and the selected access unit AU is used to search for an object.

Abstract: A scheme for realizing communications through an external network such as telephone network from a contents processing device such as AV device or PC connected to a local network such as home network is disclosed. The contents processing device solicits a set up of connection to the server device through the telephone network, to a gateway device which is connected with both the home network and the telephone network. Then, the gateway device carries out a call set up with respect to a specified address on the telephone network, upon receiving the solicitation from the contents processing device, and transfers data transmitted from the contents processing device to a connection established by the call set up, and data arriving from the connection established by the call set up to the contents processing device.

Abstract: A specific frequency extraction unit extracts a specific frequency component signal from an input image signal, a phase controller and amplitude controller control at least one of the phase and amplitude of the specific frequency component signal in accordance with watermark information, and a watermark information superposition unit superposes the specific frequency component signal on the input image signal to generate an image signal embedded with the watermark information.

Abstract: The information reproduction device for reproducing contents information based on license information added to the contents information and required for reproducing the contents information, includes a determining section for determining whether encrypted contents information is the officially copied contents information or privately copied contents information based on the contents of the license information, and a reproduction section configured to reproduce the contents information determined as the privately copied contents information by the determining section under more severe restriction that the officially copied contents information. Thus, the contents copied by the proper route (officially copied contents) can be distributed in a more advantageous form than the contents copied without proper authorization.

Abstract: A specific frequency extraction unit extracts a specific frequency component signal from an input image signal, a phase controller and amplitude controller control at least one of the phase and amplitude of the specific frequency component signal in accordance with watermark information, and a watermark information superposition unit superposes the specific frequency component signal on the input image signal to generate an image signal embedded with the watermark information.

Abstract: The information reproduction device for reproducing contents information based on license information added to the contents information and required for reproducing the contents information, includes a determining section for determining whether encrypted contents information is the officially copied contents information or privately copied contents information based on the contents of the license information, and a reproduction section configured to reproduce the contents information determined as the privately copied contents information by the determining section under more severe restriction than the officially copied contents information. Thus, the contents copied by the proper route (officially copied contents) can be distributed in a more advantageous form than the contents copied without proper authorization.

Abstract: In order to eliminate viewer's waiting time for downloading metadata on a network when enjoying hypermedia by combining videos in viewer's possession and the metadata, a client device holds video data, metadata related to the video data is recorded in a server device; the server device sends the metadata to the client device through the network at the request from the client device; and the client device processes the sent metadata, thus realizing hypermedia together with local video data.