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:
The data transfer control device of the present invention is capable of improving data transfer efficiency while discarding error data, a DMA parameter storing control unit (1112) temporarily stores parameters to a store resource; a data processing unit (1201) performs error detection processing for data that is transferred; a DMA parameter return control unit (1122) causes parameters used at transfer time of data for which the processing result in the error detection processing was an error to be returned as parameters for subsequent data transfer use from the store resource; and a completion notification delay control unit (1121), with regard to the parameters, causes the completion notification to a host system that indicates that data transfer has completed normally for each of the parameters to wait for normal completion of data transfer that uses parameters that had been set earlier than each of the first-mentioned parameters.
摘要:
The present invention performs efficient data transfer between devices. In particular, the present invention can reduce processing loads and power consumption of a response device 2 and increase overall throughput. When a request device 1 issues a direct transfer request to directly transfer data to or from a data storage unit 24 included in the response device 2, the response device 2 performs control so that data is directly transferred between a communication unit 23 and the data storage unit 24. The request device 1 is allowed to transparently and directly access the data storage unit 24 included in the response device 2 via the communication unit 24 between the request device 1 and the response device 2.
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 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 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 data transfer control device 1061 includes a read pointer update unit 5004 updating a value of a global read pointer RPg with a value of a local read pointer (first local read pointer) RP11 held by a local read pointer hold unit 5007 when completion of data transfer is recognized and a position, in an order of reading descriptors, of a descriptor D3010a indicated by the local read pointer RP11 is earlier than positions of descriptors D3010b and D3010c respectively indicated by local read pointers (second local read pointers) RP12 and RP13 held by the other data transfer control devices 1062 and 1063.
摘要:
An encryption circuit is provided which generates encrypted text from plain text using a key. The encryption circuit includes a randomized 8-bit inverse element calculation circuit which receives randomized input data that is obtained by adding, to input data on which predetermined processing is performed with the key, a predetermined input mask value determined depending on a random number, and which generates randomized output data that is obtained by adding, to an inverse element of the input data, an output mask value that is an inverse element of the input mask value, wherein the encryption circuit generates the encrypted text from the generated randomized output data.
摘要:
There has been a problem that the maximum number of logical steps increases and processing speed decreases when a masking method in which S-Box is implemented using an inverse element calculation in a composite field as a countermeasure for power analysis attack on an AES cipher.An encryption device (1) which generates encrypted text from plain text using a key, the encryption device (1) includes a randomized 8-bit inverse element calculation unit (101) which receives randomized input data that is obtained by adding, to input data on which predetermined processing is performed with the key, a predetermined input mask value determined depending on a random number, and which generates randomized output data that is obtained by adding, to an inverse element of the input data, an output mask value that is an inverse element of the input mask value, wherein the encryption device generates the encrypted text from the generated randomized output data.