Patents by Inventor Tomohide Yamamoto
Tomohide Yamamoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240067033Abstract: In order to achieve a charging service using an outlet of 100 V or 200V, the present invention provides a management server 10 including an acquisition unit 11 that acquires, from a user terminal, apparatus specifying information specifying a control apparatus that controls power supply to an outlet, and a control execution unit 12 that executes processing of controlling the control apparatus specified by the apparatus specifying information.Type: ApplicationFiled: August 24, 2023Publication date: February 29, 2024Applicant: NEC CorporationInventors: Hideyuki ISHIUJI, Hiromi SUZUKI, Yutaka OKANO, Sayaka ISHIMOTO, Shoko YOKOTE, Satoshi TANAKA, Koji KITAHARA, Megumi YAMAMOTO, Chieko KURIBAYASHI, Tomohide TOYODA
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Patent number: 11516195Abstract: To provide a terminal device that can share a session key for use in encryption communication with multiple terminal devices at a certain timing without relying on an existing server device.Type: GrantFiled: June 8, 2017Date of Patent: November 29, 2022Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Yuto Kawahara, Hitoshi Fuji, Tetsutaro Kobayashi, Reo Yoshida, Tomohide Yamamoto
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Patent number: 11388001Abstract: An encrypted communication is correctly decrypted even when key exchange completion notification is delayed. A key storage (10) stores at least one common key which is shared with another encrypted communication device. A key selecting unit (11) selects an encryption key from the at least one common key stored in the key storage (10). An encrypting unit (12) generates encrypted data by encrypting, by using the encryption key, data to be transmitted to the other encrypted communication device. A transmitting unit (13) transmits, to the other encrypted communication device, the encrypted data with a key index, by which the encryption key is uniquely identified, added thereto. A receiving unit (14) receives the encrypted data with the key index added thereto from the other encrypted communication device. A key obtaining unit (15) obtains, from the at least one common key stored in the key storage (10), a decryption key corresponding to the key index added to the encrypted data.Type: GrantFiled: July 27, 2018Date of Patent: July 12, 2022Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Reo Yoshida, Tetsutaro Kobayashi, Yuto Kawahara, Tomohide Yamamoto, Hironobu Okuyama
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Publication number: 20210091946Abstract: An encrypted communication is correctly decrypted even when key exchange completion notification is delayed. A key storage (10) stores at least one common key which is shared with another encrypted communication device. A key selecting unit (11) selects an encryption key from the at least one common key stored in the key storage (10). An encrypting unit (12) generates encrypted data by encrypting, by using the encryption key, data to be transmitted to the other encrypted communication device. A transmitting unit (13) transmits, to the other encrypted communication device, the encrypted data with a key index, by which the encryption key is uniquely identified, added thereto. A receiving unit (14) receives the encrypted data with the key index added thereto from the other encrypted communication device. A key obtaining unit (15) obtains, from the at least one common key stored in the key storage (10), a decryption key corresponding to the key index added to the encrypted data.Type: ApplicationFiled: July 27, 2018Publication date: March 25, 2021Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Reo YOSHIDA, Tetsutaro KOBAYASHI, Yuto KAWAHARA, Tomohide YAMAMOTO, Hironobu OKUYAMA
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Patent number: 10673629Abstract: A server sends a key update request for requesting updating of the key, to a client terminal. The client terminal sends, to a key delivery server, a key delivery request for requesting the delivery of a key to the client terminal. The key delivery server delivers a key to the client terminal. The client terminal sends, to the server, a key reception notice indicating that the delivered key was received. The server sends, to the client terminal, a key-use start notice indicating that the client terminal starts data transmission and reception by using the delivered key with a different client terminal from the aforementioned client terminal. The client terminal performs data transmission and reception with the different client terminal by using the delivered key.Type: GrantFiled: April 20, 2016Date of Patent: June 2, 2020Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Reo Yoshida, Hitoshi Fuji, Tetsutaro Kobayashi, Tomohide Yamamoto, Yuto Kawahara
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Patent number: 10630465Abstract: Plurality of users share a common key while permitting dynamic member change and computational complexity required for key exchange is reduced. The first key generation unit 212 of the communication devices Ui computes Ri and ci, or ci based on a twisted pseudo-random function. A session ID generation unit 113 of a key distribution device S generates sid based on a target-collision resistant hash function and transmits sid to the communication devices Ui. A second key generation unit 214 of the communication devices Ui computes Ti based on a pseudo-random function. A third key generation unit 115 of the key distribution device S computes k? and T?i based on the twisted pseudo-random function. A session key generation unit 217 of the communication devices Ui generates the common key K2 based on a pseudo-random function.Type: GrantFiled: April 14, 2017Date of Patent: April 21, 2020Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tetsutaro Kobayashi, Reo Yoshida, Hitoshi Fuji, Tomohide Yamamoto, Yuto Kawahara, Kazuki Yoneyama
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Key exchange method, key exchange system, key distribution device, communication device, and program
Patent number: 10355856Abstract: Plurality of users share a common key while permitting dynamic member change and computational complexity required for key exchange is reduced. The first key generation unit computes Ri and ci based on a twisted pseudo-random function. A session ID generation unit generates sid based on a target-collision resistant hash function and transmits (sid, R?, R?) to communication devices Ui. A second key generation unit of a representative communication device U1 computes T1 based on a pseudo-random function. A second key generation unit of general communication devices Uj computes Tj based on the pseudo-random function. A third key generation unit computes k? based on the twisted pseudo-random function and computes T?j with respect to each j. A session key generation unit of the general communication devices Uj computes Kjl and k1. The session key generation unit generates a common key K2 based on the pseudo-random function.Type: GrantFiled: April 21, 2016Date of Patent: July 16, 2019Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Reo Yoshida, Hitoshi Fuji, Tetsutaro Kobayashi, Tomohide Yamamoto, Yuto Kawahara, Kazuki Yoneyama -
Patent number: 10275960Abstract: At the time of setting authority, a management apparatus stores a database in which authority information corresponding to authority to physically drive a drive apparatus, which is a tangible object, using a terminal apparatus, and registration identification information corresponding to a subject that is given the authority are associated, and outputs information representing any of the registration identification information; and a permission apparatus receives and stores the information. At the time of exercising the authority, the terminal apparatus outputs information representing identification information, and the permission apparatus receives the information and, when the identification information corresponds to registration identification information comprised in setting information, outputs information representing authority exercise information required to exercise the authority.Type: GrantFiled: May 12, 2015Date of Patent: April 30, 2019Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Hitoshi Fuji, Tomohide Yamamoto, Tetsutaro Kobayashi, Reo Yoshida
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Publication number: 20190124058Abstract: To provide a terminal device that can share a session key for use in encryption communication with multiple terminal devices at a certain timing without relying on an existing server device.Type: ApplicationFiled: June 8, 2017Publication date: April 25, 2019Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Yuto KAWAHARA, Hitoshi FUJI, Tetsutaro KOBAYASHI, Reo YOSHIDA, Tomohide YAMAMOTO
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Patent number: 10033711Abstract: Name information which is generated by using a value corresponding to a decryption key and address information of a key cloud device which provides a cloud-key management type decryption service in which the decryption key is used are stored in a storage of a directory service device in a manner to associate the name information with the address information, and a searching unit of the directory service device searches the storage by using the inputted name information to obtain address information corresponding to the inputted name information.Type: GrantFiled: July 16, 2014Date of Patent: July 24, 2018Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tomohide Yamamoto, Go Yamamoto, Tetsutaro Kobayashi
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KEY EXCHANGE METHOD, KEY EXCHANGE SYSTEM, KEY DISTRIBUTION DEVICE, COMMUNICATION DEVICE, AND PROGRAM
Publication number: 20180183583Abstract: Plurality of users share a common key while permitting dynamic member change and computational complexity required for key exchange is reduced. The first key generation unit computes Ri and ci based on a twisted pseudo-random function. A session ID generation unit generates sid based on a target-collision resistant hash function and transmits (sid, R?, R?) to communication devices Ui. A second key generation unit of a representative communication device U1 computes T1 based on a pseudo-random function. A second key generation unit of general communication devices Uj computes Tj based on the pseudo-random function. A third key generation unit computes k? based on the twisted pseudo-random function and computes T?j with respect to each j. A session key generation unit of the general communication devices Uj computes Kjl and k1. The session key generation unit generates a common key K2 based on the pseudo-random function.Type: ApplicationFiled: April 21, 2016Publication date: June 28, 2018Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Reo YOSHIDA, Hitoshi FUJI, Tetsutaro KOBAYASHI, Tomohide YAMAMOTO, Yuto KAWAHARA, Kazuki YONEYAMA -
Publication number: 20180115414Abstract: A server sends a key update request for requesting updating of the key, to a client terminal. The client terminal sends, to a key delivery server, a key delivery request for requesting the delivery of a key to the client terminal. The key delivery server delivers a key to the client terminal. The client terminal sends, to the server, a key reception notice indicating that the delivered key was received. The server sends, to the client terminal, a key-use start notice indicating that the client terminal starts data transmission and reception by using the delivered key with a different client terminal from the aforementioned client terminal. The client terminal performs data transmission and reception with the different client terminal by using the delivered key.Type: ApplicationFiled: April 20, 2016Publication date: April 26, 2018Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Reo YOSHIDA, Hitoshi FUJI, Tetsutaro KOBAYASHI, Tomohide YAMAMOTO, Yuto KAWAHARA
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Publication number: 20170302445Abstract: Plurality of users share a common key while permitting dynamic member change and computational complexity required for key exchange is reduced. The first key generation unit 212 of the communication devices Ui computes Ri and ci, or ci based on a twisted pseudo-random function. A session ID generation unit 113 of a key distribution device S generates sid based on a target-collision resistant hash function and transmits sid to the communication devices Ui. A second key generation unit 214 of the communication devices Ui computes Ti based on a pseudo-random function. A third key generation unit 115 of the key distribution device S computes k? and T?i based on the twisted pseudo-random function. A session key generation unit 217 of the communication devices Ui generates the common key K2 based on a pseudo-random function.Type: ApplicationFiled: April 14, 2017Publication date: October 19, 2017Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tetsutaro KOBAYASHI, Reo YOSHIDA, Hitoshi FUJI, Tomohide YAMAMOTO, Yuto KAWAHARA, Kazuki YONEYAMA
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Patent number: 9735963Abstract: A private key is held which conforms to an ElGamal encryption system on a semigroup, calculation of an order of an element of the semigroup being computationally difficult, information corresponding to ciphertext conforming to the ElGamal encryption system is input, a private key s is used to decrypt the information corresponding to the ciphertext in conformance to the ElGamal encryption system, and information corresponding to a result of decrypting the ciphertext is obtained and output. Alternatively, whether it is computationally difficult or easy to calculate the order of the element of the semigroup is determined, and the safety of a decryption service providing device is evaluated based on the determination result.Type: GrantFiled: January 15, 2014Date of Patent: August 15, 2017Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tetsutaro Kobayashi, Go Yamamoto, Hitoshi Fuji, Tomohide Yamamoto, Reo Yoshida
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Publication number: 20170186255Abstract: At the time of setting authority, a management apparatus stores a database in which authority information corresponding to authority to physically drive a drive apparatus, which is a tangible object, using a terminal apparatus, and registration identification information corresponding to a subject that is given the authority are associated, and outputs information representing any of the registration identification information; and a permission apparatus receives and stores the information. At the time of exercising the authority, the terminal apparatus outputs information representing identification information, and the permission apparatus receives the information and, when the identification information corresponds to registration identification information comprised in setting information, outputs information representing authority exercise information required to exercise the authority.Type: ApplicationFiled: May 12, 2015Publication date: June 29, 2017Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Hitoshi FUJI, Tomohide YAMAMOTO, Tetsutaro KOBAYASHI, Reo YOSHIDA
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Patent number: 9693270Abstract: A control device includes: a memory; and a processor coupled to the memory and configured to: acquire congestion information indicating a congestion state of communication of wireless local area networks (LANs) which are connection destination candidates of a mobile terminal configured to switch a state thereof between a first state and a second state, in the first state the mobile terminal being wirelessly connected to a radio base station of a mobile communication network and not performing a detection operation of a wireless LAN among the wireless LANs, and in the second state the mobile terminal performing the detection operation and being wirelessly connected to a detected wireless LAN, and perform switching control for switching a state of the mobile terminal from the first state to the second state when the congestion information satisfies a given condition.Type: GrantFiled: June 19, 2014Date of Patent: June 27, 2017Assignee: FUJITSU LIMITEDInventors: Xiang Du, Tomonari Kagimoto, Tatsuya Yatsushiro, Yasushi Shigesada, Junji Satou, Tomohide Yamamoto
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Publication number: 20160148002Abstract: A key storage apparatus which prevents a service from being resumed with the same configuration as a configuration during an arithmetic processing provision period, a key storage method, and a program therefor. The key storage apparatus is such that it is assumed that, before expiration of a period for providing arithmetic processing using a key, the key is secretly managed, and that the key is outputted when the period expires, and the key storage apparatus comprises: a one-way function section causing a one-way function to act on first information to generate the key; a storage section secretly storing the first information during the period; and an expiration judging section eliminating the first information from the storage section and outputting the key when the period expires.Type: ApplicationFiled: July 2, 2014Publication date: May 26, 2016Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tetsutaro KOBAYASHI, Go YAMAMOTO, Reo YOSHIDA, Tomohide YAMAMOTO
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Publication number: 20160127335Abstract: Name information which is generated by using a value corresponding to a decryption key and address information of a key cloud device which provides a cloud-key management type decryption service in which the decryption key is used are stored in a storage of a directory service device in a manner to associate the name information with the address information, and a searching unit of the directory service device searches the storage by using the inputted name information to obtain address information corresponding to the inputted name information.Type: ApplicationFiled: July 16, 2014Publication date: May 5, 2016Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tomohide YAMAMOTO, Go YAMAMOTO, Tetsitaro KOBAYASHI
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Publication number: 20150358162Abstract: A private key is held which conforms to an ElGamal encryption system on a semigroup, calculation of an order of an element of the semigroup being computationally difficult, information corresponding to ciphertext conforming to the ElGamal encryption system is input, a private key s is used to decrypt the information corresponding to the ciphertext in conformance to the ElGamal encryption system, and information corresponding to a result of decrypting the ciphertext is obtained and output. Alternatively, whether it is computationally difficult or easy to calculate the order of the element of the semigroup is determined, and the safety of a decryption service providing device is evaluated based on the determination result.Type: ApplicationFiled: January 15, 2014Publication date: December 10, 2015Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tetsutaro KOBAYASHI, Go YAMAMOTO, Hitoshi FUJI, Tomohide YAMAMOTO, Reo YOSHIDA
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Publication number: 20150009822Abstract: A control device includes: a memory; and a processor coupled to the memory and configured to: acquire congestion information indicating a congestion state of communication of wireless local area networks (LANs) which are connection destination candidates of a mobile terminal configured to switch a state thereof between a first state and a second state, in the first state the mobile terminal being wirelessly connected to a radio base station of a mobile communication network and not performing a detection operation of a wireless LAN among the wireless LANs, and in the second state the mobile terminal performing the detection operation and being wirelessly connected to a detected wireless LAN, and perform switching control for switching a state of the mobile terminal from the first state to the second state when the congestion information satisfies a given condition.Type: ApplicationFiled: June 19, 2014Publication date: January 8, 2015Inventors: Xiang DU, Tomonari KAGIMOTO, Tatsuya YATSUSHIRO, Yasushi SHIGESADA, Junji SATOU, Tomohide YAMAMOTO