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 consisting 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:
In an authentication system, a key registration apparatus receives input of an identifier unique to a second device, generates first key data from the identifier according to a predetermined key generation algorithm, and transmits the generated first key data to a first device, which receives and stores the first key data, and authenticates the second device with use of the first key data. The second device stores in advance second key data generated from the identifier according to the predetermined key generation algorithm, and is authenticated by the first device with use of the second key data. Accordingly, the first and second devices cannot be registered without using the key registration apparatus, thereby preventing communication with unregistered devices. This enables usage of content to be limited to individual usage in the home of a user, and can be realized even with devices that are not connected outside the home.
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 computer system that makes it difficult to analyze the content of a calculation. A power operation unit (262) performs the following operations using the input data “a” and “b”: ga=ga mod n, gb=gb mod n. Next, a multiplication unit (264) performs the following calculation using ga and gb: gab=ga×gb mod n. Next, a discrete logarithm calculation unit (266) calculates ci mod pi−1 to satisfy gab=gci mod pi (i=1, 2, 3, . . . ,k). Next, a CRT unit (267) calculates “c” to satisfy ci=c mod pi−1 (i=1, 2, 3, . . . ,k) using the Chinese remainder theorem CRT.
摘要:
The present invention offers a prime calculating apparatus for achieving prime calculation where producing identical primes is avoided by simple management techniques. The prime calculating apparatus stores a known prime q and management information unique in the use range of primes. The prime calculating apparatus reads the management information; generates random information R based on the read management information; reads prime q; calculates prime candidate N, according to N=2×random information R×prime q+1, using the read prime q and generated random information R; tests whether the calculated prime candidate N is a prime; and outputs the calculated prime candidate N as a prime when the primality of the calculated prime candidate N is determined. Herewith, the prime calculating apparatus is able to calculate prime candidates from unique management information while avoiding producing identical primes.
摘要:
The present invention is a content distribution system for distributing contents. The content distribution system (1) includes a key issuing center (11), a server (12), eight output apparatuses (13a) to (13h), and a communication path (10) that connects them to each other. Here, a pair of the key issuing center (11) and each of the output apparatuses (13a) to (13h) is previously given an individual key shared between them. For example, the key issuing center (11) shares an individual key IKa with the output apparatus (13a), an individual key IKb with the output apparatus (13b), and an individual key IKh with the output apparatus (13h).
摘要:
A game system is composed of a home game execution apparatus and a portable game execution apparatus. The home game execution apparatus generates image data suitable for the image quality of the home game execution apparatus and image data suitable for the image quality of the portable game apparatus, transmits the pieces of the image data as necessary, and writes a game program to a portable recording medium. The portable game execution apparatus executes the game recorded on the portable recording medium while displaying the portable image received over the network. As a result, each game execution apparatus is able to execute the same game while displaying image data of an image quality suitable for the particular game execution apparatus.
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:
A recording and reproduction apparatus for preventing illegitimate use of contents. A recording medium stores an inherent number in an unrewritable area. The recording apparatus writes media key data and an encrypted content onto the recording medium. The media key data includes encrypted media keys generated by (i) for each of unrevoked reproduction apparatuses, encrypting a media key using a device key of the unrevoked reproduction apparatus respectively, and (ii) for each of revoked reproduction apparatuses, encrypting detection information using a device key of the revoked reproduction apparatus. The reproduction apparatus decrypts the encrypted media key using a device key to generate a decryption media key, judges whether the decryption media key is the detection information, and prohibits the encrypted content recorded on the recording medium from being decrypted when judged in the affirmative.
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.