摘要:
A key delivery apparatus that prevents improper use of contents, and manages a decryption key for decrypting encrypted content and a suppliable number showing how many times the decryption key is suppliable, with respect to one or more terminal apparatuses connected to a network. The key delivery apparatus receives a supply request for the decryption key from a terminal apparatus, and if the terminal apparatus is a legitimate supply target, judges whether the terminal apparatus is a first-type that manages a content-usage period or a second-type that does not manage the content-usage period, and if the suppliable number has a remaining number, supplies to the terminal apparatus, the decryption key and a key-usage period of the decryption key when judged that the terminal apparatus is the first-type and the decryption key when judged that the terminal apparatus is the second-type.
摘要:
A content management system formed from a playback apparatus that requests and plays content, and a content management apparatus that manages duplication and deletion of content. The playback apparatus notifies group information of the playback apparatus to the content management apparatus, acquires information from the content management apparatus showing whether requests are permitted, and duplicates/deletes content. By judging whether the playback apparatus belongs to a group, and notifying whether a duplication request is permitted or rejected, based on in-group and out-group remaining numbers that show the remaining number of duplications permitted of apparatuses in-group and out-group, respectively, the content management apparatus relaxes restrictions on in-group content duplication as compared with out-group content duplication, and thus improves convenience for users in a home network, while protecting the rights of copyright holders, with respect to content duplication and usage.
摘要:
A highly-convenient content duplication management system for allowing users to duplicate a content as long as the duplication is in compliance with a given usage right. In the system, a request destination device stores a content and a permitted number of duplications of the content. In response to a duplication request, the request destination device judges whether or not the request source device is an in-group device that belongs to the same group as the request destination device. When judging that the request source device is an in-group device, the request destination device transmits the content together with a permitted number that is equal to or smaller than the currently stored permitted number. The request destination device then updates the currently stored permitted number by subtracting the permitted number transmitted.
摘要:
In a server, an echo-request transmitting unit transmits echo-request data to a target device, and an echo-reply receiving unit receives echo-reply data from the target device. A time measuring unit measures, as the target time, the time required between transmission of the echo-request data and reception of the echo-reply data, and compares the target time with the reference time. In this way, the server judges whether the target device connected to its network belongs to a predetermined group.
摘要:
In a server, an echo-request transmitting unit 204 transmits echo-request data to a target device, and an echo-reply receiving unit 205 receives echo-reply data from the target device. A time measuring unit 206 measures, as the target time, the time required between transmission of the echo-request data and reception of the echo-reply data, and compares the target time with the reference time. In this way, the server judges whether the target device connected to its network belongs to a predetermined group.
摘要:
In a server, an echo-request transmitting unit 204 transmits echo-request data to a target device, and an echo-reply receiving unit 205 receives echo-reply data from the target device. A time measuring unit 206 measures, as the target time, the time required between transmission of the echo-request data and reception of the echo-reply data, and compares the target time with the reference time. In this way, the server judges whether the target device connected to its network belongs to a predetermined group.
摘要:
A server and a client hold common secret information in respective secret information holding units. A server Cyclic Redundancy Check (CRC) unit in the server generates a CRC code after adding the secret information to communication data, and transmits the communication data with the CRC code attached. A client CRC unit of the client generates a CRC code after adding the secret information to communication data, and checks whether or not an error has occurred in the communication data on the communication path. Since the client holds the secret information, the client determines that an error has not occurred, and obtains the communication data. On the other hand, a router, which does not hold the secret information, is unable to obtain the communication data. This prevents the communication data from being transferred to devices outside an authorized domain.
摘要:
A content distribution system in which content transmission/reception is suppressed when there is a high risk of contents being stolen by a third party during communication. A content server acquires a communication distance indicating how far the content server is from a terminal in data communication. The content server conducts content transmission/reception when the communication distance is less than or equal to a predetermined value, and suppresses content transmission/reception when the communication distance exceeds the predetermined value.
摘要:
A group management device provides with a content a device included in a group managed by the group management device. The group management device includes a storage unit that stores a total number of remote device that the group management device currently registers, a maximum number of remote devices that the group management device is permitted to register, a total number of local device that the group management device currently registers, and a maximum number of local devices that the group management device is permitted to register. The group management device also includes a judging unit that judges whether the total number of the remote device exceeds the maximum number of the remote devices when it is judged that the one device is the remote device. The judging unit judges whether the total number of the local device exceeds the maximum number of the local devices when it is judged that the one device is the local device.
摘要:
A group management device provides with a content a device included in a group managed by the group management device. The group management device includes a storage unit that stores a total number of remote device that the group management device currently registers, a maximum number of remote devices that the group management device is permitted to register, a total number of local device that the group management device currently registers, and a maximum number of local devices that the group management device is permitted to register. The group management device also includes a judging unit that judges whether the total number of the remote device exceeds the maximum number of the remote devices when it is judged that the one device is the remote device. The judging unit judges whether the total number of the local device exceeds the maximum number of the local devices when it is judged that the one device is the local device.