摘要:
A data processing device for playing back a digital work reduces the processing load involved in verification by using only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on a DVD. In addition, the data processing device improves the accuracy of detecting unauthorized contents by randomly selecting a predetermined number of encrypted units every time the verification is performed.
摘要:
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.
摘要:
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.
摘要:
A content distribution system for transferring contents between transmission device and reception device. The transmission device includes: key obtaining unit that obtains, from reception device, public keys and public key identifiers; watermark embedding unit that embeds a different public key identifier, as electronic watermark, into each of contents that are identical in substance; an encryption unit that encrypts contents using public keys to generate encrypted contents; and transmission unit that transmits encrypted contents to reception device. The reception device includes: key storage unit storing public keys, public key identifiers, and a private key that makes a pair with one of the public keys; key transmission unit that transmits public keys and public key identifiers to the transmission device; content receiving unit that receives encrypted contents from transmission device; and decryption unit that obtains a content from the received encrypted contents, using the private key.
摘要:
A battery history information management device for managing history information of a secondary battery includes: a connection determination unit which determines whether a charge/discharge device connected to the secondary battery is (i) a first charge/discharge device connected via a communication network to a server which manages the history information or (ii) a second charge/discharge device not connected to the server; a battery history recording unit which records, when it is determined that the charge/discharge device is the second charge/discharge device, charge/discharge history for second charge/discharge device into battery history data; and a history upload control unit which transmits, when it is determined that the charge/discharge device is the first charge/discharge device, the battery history data to the server via the first charge/discharge device.
摘要:
The present invention provides a password recovery system that re-supplies a password to only the legitimate user of the password. The password recovery system includes a memory card with CPU and a mobile phone. When a password needs to be recovered, a phone call is made, to the mobile phone, from a telephone connected to a phone line whose phone number is registered in advance into the memory card with CPU. The mobile phone then obtains the telephone number of the phone line via a caller's telephone number notifying service. It is judged whether the obtained telephone number and the registered phone number are the same, and when they are the same, the password stored in the memory card with CPU will be re-supplied so that the user can recover it.
摘要:
In a content-log analyzing system, content includes additional information indicating, according to a property of the content, whether or not to record communication of the content in a content-log. When transmitting content to a TV or a PC, a data-communication controlling device judges whether or not to record the communication in a content-log based upon additional information of the content, and when judging affirmatively, generates and stores content-log information. A content-log analyzing server obtains the content-log stored in the data-communication controlling device, and analyzes the obtained content-log.
摘要:
A content distribution system distributes contents. The content distribution system includes a key issuing center, a server, eight output apparatuses, and a communication path that connects them to each other. The key issuing center and each of the output apparatuses are previously given an individual key shared between them. For example, the key issuing center shares individual key IKa with an output apparatus, individual key IKb with an output apparatus, and individual key IKh with an output apparatus.
摘要:
Provided is a program conversion apparatus for generating a secret holding program, which disables a malicious analyzer from analyzing the an original program easily.The program conversion apparatus generates a first instruction group for acquiring values to assign to selection parameters; a second instruction group that includes an instruction group for acquiring, based on an arithmetic expression that uses the selection parameters, a selection identifier showing a selection-target data piece to be processed next; a third instruction group for updates a value of each selection parameter so as to reflect one of (a) a selection identifier showing one of the selection-target data pieces that has already been processed, and (b) at least one of one or more values that have already been assigned to the selection parameters; and selection-target data pieces that, by processing in a predetermined order, output an execution result identical to a result of the original program, each of the selection-target data pieces being in correspondence with a different selection identifier. The program conversion apparatus generates the secret holding program so as to include the first instruction group, the second instruction group, the third instruction group and the selection-target data pieces.
摘要:
A signature generation apparatus is capable of making a value used in signature generation processing difficult to analyze. In the signature generation apparatus, a random number generation module generates a len-bit random number u, a selection module converts the generated random number u into a bit expression, and acquires element pairs corresponding to the bit values from a table memory unit. A random element generation module applies a basic operation of a first group G and a second group to all acquired element pairs, and calculates an element Pk on the first group G and an element Pak on the second group Ga. The signature generation apparatus generates a digital signature S for a message m with use of a transformation module, a main operation module, an inverse transformation module, a multiplication module, a division module, and a signature data generation module.