Nippon Telegraph and Telephone Corporation

Other

The Furukawa Electric Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Kabushiki Kaisha Toshiba

Satoshi Ono

Shin Miyakawa

Yusuke Hisada

Kazuyuki Terao

Yukio Tsuruoka

Akira Kabumoto

Eiichi Horita

Akira Takura

Naoki Yoshida

Shinya Mizone

Kiyoshi Nakayama

Masayasu Ito

Keiji Ishikawa

Haruhisa Ichikawa

Shigeru Hiura

Hidetaka Ishimoto

Shoouji Nakajima

An address notification device is provided with: a link information list storage partfor storing link information list composed of link information including an own address, an address of a communicating party, and process information about processing of communication information to be communicated between the own address and the communicating party address; a change information registration partfor adding the link information selected by a link information select partwith change information representing the content of the change; a link change information sending partfor sending link change information representing a change of the link information to a destination indicated by the communicating party address contained in the link information added with the change information; and a link information change partfor changing the link information on the basis of the change information added thereto in response to response information sent from the communicating party in response to the sending thereto of the link change information.

Address notifying apparatus and address notifying method

A mediating apparatus is provided on an IP network, and stores an access control list (ACL) retained in a VPN gateway unit. The mediating apparatus: receives a retrieval request from a VPN client unit; acquires a private IP address of a communication unit by reference to ACL; searches DNS to acquire therefrom an IP address of the VPN gateway unit; generates a common key that is used for authentication between the VPN client unit and the VPN gateway unit and for encrypted communication therebetween; sends the IP address of the VPN gateway unit, the private IP address of the communication unit, and the common key to the VPN client unit; and sends the IP address of the VPN client unit and the common key to the VPN gateway unit.

Remote access VPN mediation method and mediation device

An event-ordering certification systemincludes a certification apparatus, a plurality of user apparatuses(i=a, b, . . . , n), an audit apparatusfor performing an audit of an event-ordering receipt published by the certification apparatusand a networkfor connecting these elements with each other. In response to an event-ordering request from one user apparatus, the certification apparatuspublishes the event-ordering receipt and sends it to the user apparatus. If a mistrust is produced in the event-ordering receipt, the user apparatusverifies the event-ordering receipt with the use of data published by the certification apparatusand an audit result by the audit apparatus

Event-ordering certification method

An email access control scheme capable of resolving problems of the real email address and enabling a unique identification of the identity of the user while concealing the user identification is disclosed. A personalized access ticket containing a sender's identification and a recipient's identification in correspondence is to be presented by a sender who wishes to send an email to a recipient so as to specify the recipient as an intended destination of the email. Then, accesses between the sender and the recipient by verifying an access right of the sender with respect to the recipient according to the personalized access ticket at a secure communication service. Also, an official identification of each user by which each user is uniquely identifiable by a certification authority, and an anonymous identification of each user containing at least one fragment of the official identification are defined, and each user is identified by the anonymous identification of each user in communications for emails on a communication network.

Email access control scheme for communication network using identification concealment mechanism

In a distributed digital signature generation method, the method includes the steps of: generating partial signature keys by distributed processes, generating partial digital signatures by using the partial signature keys for the hash value of an input digital document to which additional information such as time is added, combining a predetermined threshold number of partial digital signatures, performing a transformation process on the partial digital signatures according to the combination, and generating an integrated digital signature from the result of the transformation process, in which a least common multiple of predetermined values is used as a transformation number, and it is judged whether an incorrect partial digital signature exists and the number is one, and the incorrect partial digital signature is identified when the number is one.

Distributed digital signature generation method and digitally signed digital document generation method and apparatus

The present invention is directed to a speaker using lightweight, highly rigid diaphragm having excellent frequency characteristic and improving resistance to environment (including resistance to UV and resistance to fading). For this end, the speaker utilizes a cone-shaped diaphragm made from foamed or cellular resin such as polyethylene terephthalate (PET) resin or polyethylene naphthalate (PEN) resin with 30 &#x3bc;m average cell size. The use of such cone-shaped diaphragm is effective to improve sound quality of the speaker.

Loudspeaker

In a time stamping system formed by a client device and a server device, the client device includes a digest generation unit for generating a plurality of digests for a plurality of digital documents, a digest combining unit for combining the plurality of digests generated by the digest generation unit, a unified digest generation unit for generating a unified digest from the plurality of digests as combined by the digest combining unit, a transmission unit for transmitting a time stamping request containing the unified digest generated by the unified digest generation unit, to the server device, and a reception unit for receiving a time stamp token for the plurality of digital documents from the server device. The server device generates the time stamp token containing a time stamped digital document obtained by combining the unified digest and a time information acquired in response to the time stamping request, and a digital signature for the time stamped digital document.

Folder type time stamping system and distributed time stamping system

A communication scheme capable of guaranteeing the order of packets in the communication media exchange during the communication so as to be able to continue the communication smoothly even after the communication media exchange is disclosed. The source host transmits a first check packet through the first communication path and stops transmission of user data packets upon transmitting the first check packet, while the destination host transmits the first check packet through the second communication path upon receiving the first check packet through the first communication path while transmitting a second check packet through the first communication path, and stops transmission of user data packets upon transmitting the second check packet. Then, the source host starts transmission of user data packets through the second communication path upon receiving the first check packet through the second communication path, while the destination host starts transmission of user data packets through the second communication path upon receiving the second check packet through the second communication path.

Communication scheme using check packets for guaranteeing data packet order in communication media exchange during communication

An L2 integrated access (L2IA) system is constructed from: L2IA subscribers for supporting communications between user terminals using various communication media, each L2IA subscriber having an L2IA identifier for uniquely identifying each L2IA subscriber within the L2 integrated access system and a terminal ID for uniquely identifying each L2IA subscriber within each communication medium associated with each L2IA subscriber; and an L2IA relay network formed by relay units to be connected with the L2IA subscribers through various communication media and relaying communications between the L2IA subscribers through the L2IA relay network, each relay unit being provided in correspondence to one communication medium such that at least one relay unit is provided in correspondence to each communication medium, and each relay unit having an L2IA relay ID for uniquely identifying each relay unit within the L2IA relay network and a terminal ID for uniquely identifying each relay unit within each communication medium associated with each relay unit, and an LPR (Location and Preference Register) for registering an RLD (Registered Location Data) indicating a terminal ID of an L2IA subscriber and an L2IA relay ID of a relay unit for each potentially available communication medium in correspondence to the L2IA identifier of each L2IA subscriber, such that the relay unit relays the communications between the L2IA subscribers according to the RLDs registered in correspondence to the L2IA identifies of the L2IA subscribers.

Layer 2 integrated access scheme

A packet multiplexer capable of realizing the optimization of a communication path automatically, without requiring a user to explicitly specify for it, is disclosed. The packet multiplexer is formed by a plurality of first communication interfaces for terminating a plurality of C-plane and U-plane pairs on one side of the packet multiplexer, a second communication interface for terminating a single C-plane and a plurality of U-planes on another side of the packet multiplexer, a connection interface for multiplexing the C-plane and U-plane pairs terminated at the first communication interfaces into the single C-plane and the plurality of U-planes terminated at the second communication interface, and a control unit for controlling multiplexing of U-planes by the connection interface according to signaling through C-planes, such that a cut-through is made within the packet multiplexer between two U-planes terminated at the first communication interfaces that form a loop.

Packet multiplexer with automatic communication path optimization based on loop detection

In manufacturing a foamed plastics of a saturated polyester resin, in which a saturated polyester resin is melted in an extruder, a foaming agent is injected under pressure into the molten saturated polyester resin at an intermediate portion of a barrel of the extruder, and the molten saturated polyester resin containing the foaming agent is extruded from a die to manufacture the foamed plastics of the saturated polyester resin, a polydimethylsiloxane having a boiling point, which is lower by at least 50.degree. C. than the melting point of the saturated polyester resin to be foamed, at the atmospheric pressure is used as a foaming agent.

Growing community of inventors

Tokyo, Japan

Satoshi Ono