Nippon Hoso' Kyokai

Nec Corporation

Yusei Nishimoto

Tatsuya Kurioka

Seiichi Namba

Toshihiro Uehara

Jun Goto

Haruo Okuda

Kiyohiko Ishikawa

Akitsugu Baba

Syunji Sunasaki

Satoshi Fujitsu

Haruyuki Nakamura

A low cost scramble key management apparatus which enables to manage a scramble key based on individual contract information and to ensure security in narrow band broadcasting. The scramble key management apparatusincludes an ECM decoding unitfor decoding an ECM in which a scramble key and individual contract information are encrypted. The individual contract information includes contract information indicating contract statuses of a plurality of content receivers, . . . which is arranged based on receiver IDs for identifying each of the content receivers. The scramble key management apparatusincludes a contract information obtaining unitfor obtaining the contract information of the content receiverassociated with the receiver ID from the individual contract information and a contract status determining unitfor determining the contract status and outputting the scramble key to a content decoderif the contract status is under contract.

Scramble key management unit, scramble key management information transmitting unit, method for scramble key output management, scramble key management program, license information management unit, license management information transmitting unit, method for license information output management, and license information management program

The present invention provides an access control method of controlling acceptance or rejection of access to content from metadata. The access control method according to the present invention includes a step of producing metadataA for contentA and embedding a digital signatureA of a producer who has produced the metadata as producer information in the produced metadataA, a step of embedding an identifierA indicating which metadata are accessible to the content in license information required to play back the contentA, and an access propriety control step of comparing the digital signatureA with the identifierA to control propriety of access to the contentA from the produced metadataA.

Access control method, access control system, metadata controlling device, and transmitting apparatus

A content transmission method, a content reception method, an apparatus and a computer program using same, that improve the efficiency of descrambling a scrambled content, make the management of cryptography keys for descrambling easy, and protect the copyright of contents, are provided. A content transmission apparatusthat encrypts and transmits contents and a content reception apparatusthat receives the encrypted contents are provided. The content transmission apparatusincludes a content scrambling unitthat encrypts contents using a scrambling key Ks, a content key , a work key Kw, a master key Km, and a multiplexing unitthat transmits multiplexed contents. The content reception apparatusincludes a separating unitthat receives and separates the multiplexed encrypted content, and a content descrambling unitthat obtains the contents by descrambling encrypted information separated by the separating unit

Content transmission apparatus, content reception apparatus, content transmission program, and content reception program

A method of transmitting contents, which are to be received at a reception side where a portion of the contents is previewed while the contents are not accessible for playing other than for a preview purpose, includes the steps of encrypting the contents by a first encryption key, generating information indicative of an elapsed time of the contents that indicates a relationship between positions on a time axis of the contents representing an amount of time that passes as the contents are played and a time count that accrues as a preview time when the contents are previewed, encrypting the first encryption key and the information indicative of an elapsed time of the contents by a second encryption key, thereby generating first encrypted information, encrypting the second encryption key and content-usage control information by a third encryption key, thereby generating second encrypted information, the content-usage control information indicating usage of the contents on the reception side, and transmitting the encrypted contents, the first encrypted information, and the second encrypted information to the reception side.

Diligent control of preview of stored contents

A method of transmitting a content to a reception side includes the steps of encrypting the content by use of a scramble key that varies with time, encrypting scramble-key-associated information that includes at least the scramble key and usage-control information, the usage-control information indicative of usage of the content on the reception side, and transmitting the encrypted content and the encrypted scramble-key-associated information to the reception side.

Growing community of inventors

Tokyo, Japan

Yusei Nishimoto