Abstract: A system structured from a management device, a content key distribution device and a plurality of terminals suppresses the data volume of a terminal revocation list (TRL). The management device generates and transmits a TRL formed from data that expresses terminal IDs of all terminals to be invalidated, by only a value and a position of a common bit string in the IDs, to the content key distribution device. Each terminal holds a terminal ID that includes a manufacturer ID and a serial number, and requests the distribution of a content key by sending the terminal ID to the content key distribution device. The content key distribution device refers to the TRL, judges whether the terminal ID transmitted from the terminal is that of an invalidated terminal, and if negative, encrypts and transmits the content key to the terminal.

Abstract: A display device with a touch sensor according to the present invention includes an active matrix substrate 4A and a transparent counter electrode 7. On a first surface of the active matrix substrate, multiple pixel electrodes are arranged in matrix. The transparent counter electrode is opposed to the first surface of the active matrix substrate. The display device further includes a first circuit, a second circuit and a switching circuit. The first circuit supplies a voltage or a current to the transparent counter electrode for display purposes. The second circuit detects currents flowing from a number of points on the transparent counter electrode. And the switching circuit selectively connects electrically one of the first and second circuits to the transparent counter electrode.

Abstract: The management apparatus 105a manages copying of information from an original recording medium 101a to a copy recording medium 102a. The management apparatus 105a comprises: a transmission/reception unit 701a configured to receive an original-medium identifier from the copying apparatus 104a and to transmit permission information to the copying apparatus 104a, the original-medium identifier identifying the original recording medium, and the permission information indicating permission for the copying of the information; and a control unit 708a configured to determine whether to permit the copying of the information based on the received original-medium identifier and a registered original-medium identifier that identifies a registered original recording medium, and to allow the transmission/reception unit 701a to transmit the permission information when determining to permit the copying.

Abstract: To provide a backup management device that deletes a content so as to be restorable in the future while protecting a copyright of the content, in a case where there exists a backup of the content. In an HD recorder, a first information storage unit stores a content, a second information storage unit stores a backup of the content, a secure storage unit stores a hash value of the content. If receiving an instruction to delete the content so as to be restorable, a control unit deletes the content from the first information storage unit. When the content is played back, an encryption processing unit applies a calculation to the content to generate detection information, and the control unit compares the hash value with the detection information to judge whether the content has been tampered.

Abstract: When a PC transmits a content request to a device registration apparatus in which a permitted number of devices have already been registered, an expiration time management unit judges whether any registration information registered in a registration list management unit has an exceeded registration expiration time. If registration information with an exceeded registration expiration time is registered in the registration list management unit, the registration list management unit deletes this registration information, and newly registers registration information of the PC.

Abstract: A recording device performs recording on a recording medium such as a DVD, and playback compatibility of the recording medium is increased. In circumstances such as when a standard is established after the manufacture of a playback apparatus, there are playback devices that physically cannot read information for decrypting encrypted data from a predetermined area of the recording medium due to the specifications of the playback apparatus, and therefore the playback apparatus cannot use the recording medium. In order for the recording medium to be able to be used in such a playback apparatus, the recording device reads data recorded in the predetermined area of the recording medium, and records the read data in another area that is readable by the playback apparatus.

Abstract: A time authentication device identifies clocks that show a time falling within the predetermined permissible range as compared with a time shown by the time authentication device. In a time authentication device embodied as a distribution device, a time-relation information storage unit stores a playback-device-time measured by a clock unit of a playback device, and also stores a distribution-device-time measured by a clock unit when the playback-device-time is acquired. The time authentication unit acquires from the playback device a target time measured by the clock unit, and also acquires an authentication time measured by the clock unit when the target time is received. The time authentication unit then calculates a first difference, a second difference, an authentication difference. If the authentication difference is smaller than or equal to a predetermined threshold, the time authentication unit judges that the clock unit of the playback device is valid.

Abstract: Provided is a new system for content use and settlement. A user requests a mobile telephone charge management server (3000) to perform proxy settlement for goods purchased using mobile telephones 1 (4100), 2 (4200) and 3 (4300). The mobile telephone charge management server (3000) makes an inquiry to a registration server (3100) as to whether or not proxy settlement is possible. When proxy settlement is not possible, the mobile telephone performs settlement using electronic money that has been deposited therein.

Abstract: The present invention provides an apparatus for securely acquire a circuit configuration information set corresponding to a new cryptosystem without increasing the number of reconfigurable circuits. A content playback apparatus 100 includes an FPGA 122 that is reconfigurable. The content playback apparatus 100 stores a decryption circuit program that shows the structure of a decryption circuit that executes decryption in accordance with a prescribed cryptosystem. The FPGA is reconfigured in accordance with the program to configure the decryption circuit. The playback apparatus 100 acquires, from outside, an encrypted file that has been generated by encrypting a file including a decryption circuit program corresponding to the new cryptosystem in accordance with the prescribed cryptosystem, and decrypts the encrypted file by the decryption circuit.

Abstract: Disclosed is a group admission system having a client and a server that belongs to a closed group within which contents are available. The client determines whether it is permissible to request to join the group to be a member device thereof based on the number of groups that the client is in and the maximum number of groups that the client is permitted to be in. If permissible, the client transmits a registration request to the server with information unique to the client. The server determines whether to permit the client to join the group by registering with the server based on the number of member devices registered with the server and the maximum number of member devices registerable with the server. If it is permitted, the server registers the unique information, and transmits group identification information to the client. The client receives and stores the group identification information.

Abstract: Processing load on an executing device for conducting playback is high during the playback of contents since the executing device performs verification of the contents validity in parallel with the contents playback, and therefore the executing device has to be equipped with a highly efficient processor. The present invention reduces the processing load involved in the verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on the DVD. In addition, the present invention is capable of improving the accuracy of detecting unauthorized contents to some extent by randomly selecting a predetermined number of encrypted units every time the verification is performed.

Abstract: To provide a content playback device capable of protecting content according to DRM, when decrypting encrypted content recorded on a recording medium and playing the decrypted content. If key generation information is “00”, a key control unit 104 concatenates a decrypted media key and content information in this order, and applies a one-way function to the concatenation result to generate a content key. If the key generation information is “10”, the key control unit 104 sets a rights key as the content key. If the key generation information is “01”, the key control unit 104 concatenates the decrypted media key and the rights key in this order, and applies a one-way function to the concatenation result to generate the content key.

Abstract: A content recommendation device and a content recommendation method that recommend appropriate content with appropriate timing are provided. The content recommendation device (300) is a content recommendation device (300) which recommends content to a user as recommended content, and which includes a recommended content determining unit (330) which determines second content as the recommended content, the second content being related to first content that is at least partially viewed by the user and a recommendation timing determining unit (350) which determines a recommendation timing for presenting information of the recommended content, based on a chronological relationship between the recommended content and third content which is related to the recommended content and is currently available or will be available for viewing.

Abstract: To provide a content playback device capable of protecting content according to DRM, when decrypting encrypted content recorded on a recording medium and playing the decrypted content. If key generation information is “00”, a key control unit 104 concatenates a decrypted media key and content information in this order, and applies a one-way function to the concatenation result to generate a content key. If the key generation information is “10”, the key control unit 104 sets a rights key as the content key. If the key generation information is “01”, the key control unit 104 concatenates the decrypted media key and the rights key in this order, and applies a one-way function to the concatenation result to generate the content key.

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 copyright protection system is provided that keeps manufacturing costs down regardless of the total number of playback apparatuses belonging to the system. In this system, a device key generating unit of a key management apparatus performs a modular exponentiation operation on a random number with an inverse element of a product of predetermined prime numbers, so as to generate and distribute device keys to playback apparatuses in one-to-one correspondence. A key revocation data generating unit generates, as key revocation data, information identifying the prime numbers used by an unrevoked playback apparatus to generate a decryption key from its device key and distributes the key revocation data along with an encrypted content to each playback apparatus. Playback apparatuses each attempt to generate a description key based on the key revocation data, and only those playback apparatuses that have successfully generated a decryption key are able to decrypt the encrypted content.

Abstract: An electronic money usage system is capable of preventing dishonest use of electronic money recorded on a recording medium. A memory card 300 acquires signature-type electronic data from a bank server apparatus 100, and generates a first authenticator using the received first authenticator, and an identification flag, an electronic money ID and an amount included in the electronic money. When a user uses the signature-type electronic money, the memory card 300 generates a second authenticator with use of a second password received from the user, and the identification flag, electronic money ID and amount included in the electronic money. The memory card 300 outputs the electronic money if the first authenticator and the second authenticator match.

Abstract: A digital camera comprising: an imaging unit operable to generate an image by photographing an object; a receiving unit operable to receive information relating to image processing from one or more transmission devices; a judging unit operable to judge whether the image is to be output or not, based on the information received by the receiving unit; and an output unit operable to, in accordance with the judgment made by the judging unit, output the image to a memory, or discard the image, where the memory is readable by the digital camera or an external device.

Abstract: Processing load on an executing device for conducting playback is high during the playback of contents since the executing device performs verification of the contents validity in parallel with the contents playback, and therefore the executing device has to be equipped with a highly efficient processor. The present invention reduces the processing load involved in the verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on the DVD. In addition, the present invention is capable of improving the accuracy of detecting unauthorized contents to some extent by randomly selecting a predetermined number of encrypted units every time the verification is performed.

Abstract: A recording/playback apparatus is capable of using pre-image-converted content in a case of transferring an image-converted content to another device, then back from transfer-destination device to the recording/playback apparatus. The recording/playback apparatus includes a storage unit that stores a first encrypted content generated by encrypting the content, a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and a content key for decryption of the first and second encrypted contents, a key transfer unit that writes the content key to the external recording medium, and erases the content key stored in the storage unit, and a content transfer unit that, after the content key has been erased, writes the second encrypted content to the external recording medium, and erases the second encrypted content from the storage unit.