Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Tomoya Sato

Makoto Fujiwara

Isao Kidoguchi

Toru Takayama

Norihiko Mizobata

Kazuhisa Tanaka

Kentaro Shiomi

Kazuya Shimizu

In the case where a target device stores: m keys {Ka, . . . , Kam} (m is a natural number) in a manner that the Kai (i is a natural number satisfying 1&#x2266;i&#x2266;m) is encrypted with the Ka (i&#x2212;1); and n keys {Kb, . . . , Kbn} (n is a natural number) in a manner that the Kbj (j is a natural number satisfying 1&#x2266;j&#x2266;n) is encrypted with the Kb (j&#x2212;1), a confidential information processing unit is caused to perform a processing of re-encrypting the encrypted key Enc (Kai, Ka (i&#x2212;1)), which has been encrypted with the Ka (i&#x2212;1), by using the Kb (j&#x2212;1) and outputting as an encrypted key Enc (Kai, Kb (j&#x2212;1)).

Confidential information processing host device and confidential information processing method

In order to maintain the confidentiality of information at a high level even in cases where a confidential information processor in which multiple types of decryption sequences are applicable is used, decryption is performed according to the value of content decryption information. If the value of the content decryption informationis '0', an encrypted content keyis decrypted with a selected authentication intermediate keyand encrypted contentsare decrypted with a content key. On the other hand, if the value of the content decryption informationis other than '0', the selected authentication intermediate keyis converted by performing an arithmetic operation using that value, thereby generating a conversion intermediate key. An encrypted domain keyis decrypted with the conversion intermediate key, the encrypted content keyis decrypted with a domain key, and then the encrypted contentsare decrypted with a content key

Confidential information processing method, confidential information processor, and content data playback system

The semiconductor laser device includes a cavity structure having a first clad layer, an active layer and a second clad layer formed on a substrate. The second clad layer has a stripe portion extending between the front end face from which laser light is extracted and the rear end face opposite to the front end face. The stripe portion has a first region located closer to the front end face, a second region located closer to the rear end face and a change region whose width changes located between the first and second regions. The effective refractive index difference between the inside and outside of the stripe portion in the change region is greater than that in the first region.

Semiconductor laser device and fabrication method for the same

A demultiplexer circuit which can simultaneously demultiplex plural pieces of input data while minimizing the circuit scale. The demultiplexer circuit includes an input line identification information addition circuitfor giving input line identification information to input data which have data identification information and are inputted through plural input lines, respectively; a multiplexerfor outputting the input data which have been given the input line identification information, respectively, by the input line identification information addition circuitthrough one common line; a filterfor filtering the data outputted from the multiplexeron the basis of the input line identification information and the data identification information at one time; and a filter tablethat contains filtering conditions which are used in the filter

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Osaka, Japan

Tomoya Sato