Patents by Inventor Masahide Sasaki

Masahide Sasaki 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).

  • Patent number: 11502831
    Abstract: A quantum key distribution device is provided with an encoding unit which encodes an optical pulse train; an intensity modulating unit which subjects the encoded optical pulse train to N (where N is an integer at least equal to 3) types of intensity modulation having mutually different intensities, with different timings; and a first key distillation processing unit which generates an encryption key on the basis of a data sequence obtained by removing data obtained from an optical pulse having a specific modulation pattern from a data sequence used by the encoding unit and the intensity modulating unit.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: November 15, 2022
    Assignees: NEC CORPORATION, NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, National University Corporation Hokkaido University
    Inventors: Ken-ichiro Yoshino, Mikio Fujiwara, Masahide Sasaki, Akihisa Tomita
  • Publication number: 20220147640
    Abstract: A secret sharing storage system includes at least one user terminal, n units (n: an integer of 2 or more) of storage devices, and a main controller that is communicably connected to a random number generator. The main controller acquires a random number generated by the random number generator in a case of receiving original data sent from the user terminal, executes distributed processing on the original data by using the random number to generate n pieces of distributed data, and stores the n pieces of distributed data respectively in the corresponding n units of storage devices.
    Type: Application
    Filed: January 21, 2020
    Publication date: May 12, 2022
    Applicants: PANASONIC CORPORATION, NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY
    Inventors: Masakatsu MATSUO, Katsunori KOGATA, Masahide SASAKI, Mikio FUJIWARA
  • Publication number: 20190245685
    Abstract: A quantum key distribution device is provided with an encoding unit which encodes an optical pulse train; an intensity modulating unit which subjects the encoded optical pulse train to N (where N is an integer at least equal to 3) types of intensity modulation having mutually different intensities, with different timings; and a first key distillation processing unit which generates an encryption key on the basis of a data sequence obtained by removing data obtained from an optical pulse having a specific modulation pattern from a data sequence used by the encoding unit and the intensity modulating unit.
    Type: Application
    Filed: August 31, 2017
    Publication date: August 8, 2019
    Applicants: NEC CORPORATION, NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATION UNIVERSITY, NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY
    Inventors: Ken-ichiro YOSHINO, Mikio FUJIWARA, Masahide SASAKI, Akihisa TOMITA
  • Patent number: 10193874
    Abstract: Provided is a communication system in which a terminal communicates with a server via a portable communication network used for communication between smartphones. The smart phone includes first pre-shared key and encryption keys, the terminal includes a second pre-shared key, the server includes the encryption keys same as the encryption keys included in the smartphone, authentication between the terminal and the smartphone is performed by using the first pre-shared key and the second pre-shared key, and the terminal and the server perform communication via the smartphone by performing key synchronization of the encryption keys while setting a hash value of the encryption keys as an ID.
    Type: Grant
    Filed: November 9, 2016
    Date of Patent: January 29, 2019
    Assignee: NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY
    Inventors: Mikio Fujiwara, Masahide Sasaki
  • Publication number: 20170134351
    Abstract: Provided is a communication system in which a terminal communicates with a server via a portable communication network used for communication between smartphones. The smart phone includes first pre-shared key and encryption keys, the terminal includes a second pre-shared key, the server includes the encryption keys same as the encryption keys included in the smartphone, authentication between the terminal and the smartphone is performed by using the first pre-shared key and the second pre-shared key, and the terminal and the server perform communication via the smartphone by performing key synchronization of the encryption keys while setting a hash value of the encryption keys as an ID.
    Type: Application
    Filed: November 9, 2016
    Publication date: May 11, 2017
    Applicant: NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIO NS TECHNOLOGY
    Inventors: Mikio FUJIWARA, Masahide SASAKI
  • Patent number: 8509446
    Abstract: It is an object of the present invention to provide a network system for quantum key distribution (QKD) for free space and fiber networks. The system of the present invention generates a couple of photons which have different wavelength and inputs each of the photons into the asymmetric Mach-Zehnder interferometer to obtain time-bin entangled state. It provides polarization information with one part of the photons. Then it can obtain hybrid quantum entanglement. The system of the present invention may be used hybrid quantum key distribution system applied for both free space and fibers.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: August 13, 2013
    Assignees: National Institute of Information and Communications Technology, NEC Corporation
    Inventors: Mikio Fujiwara, Morio Toyoshima, Masahide Sasaki, Akihisa Tomita, Yoshihiro Nambu, Ken-ichiro Yoshino
  • Patent number: 8048731
    Abstract: A method for reducing low frequency noise of a transistor operable at cryogenic temperatures includes a first step in which the transistor is illuminated with a light in a state that the transistor is activated and flowed current by supplying a power at a predetermined temperature, and a second step in which the transistor is operated at the predetermined temperature after the illumination of the light.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: November 1, 2011
    Assignees: National Institute of Information and Communications Technology, National Institutes of Natural Sciences
    Inventors: Mikio Fujiwara, Masahide Sasaki, Hiroshi Matsuo, Hirohisa Nagata
  • Publication number: 20110170695
    Abstract: It is an object of the present invention to provide a network system for quantum key distribution (QKD) for free space and fiber networks. The system of the present invention generates a couple of photons which have different wavelength and inputs each of the photons into the asymmetric Mach-Zehnder interferometer to obtain time-bin entangled state. It provides polarization information with one part of the photons. Then it can obtain hybrid quantum entanglement. The system of the present invention may be used hybrid quantum key distribution system applied for both free space and fibers.
    Type: Application
    Filed: December 28, 2010
    Publication date: July 14, 2011
    Applicants: NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, NEC CORPORATION
    Inventors: Mikio FUJIWARA, Morio TOYOSHIMA, Masahide SASAKI, Akihisa TOMITA, Yoshihiro NAMBU, Ken-ichiro YOSHINO
  • Publication number: 20100237934
    Abstract: A method for reducing low frequency noise of a transistor operable at cryogenic temperatures includes a first step in which the transistor is illuminated with a light in a state that the transistor is activated and flowed current by supplying a power at a predetermined temperature, and a second step in which the transistor is operated at the predetermined temperature after the illumination of the light.
    Type: Application
    Filed: March 18, 2009
    Publication date: September 23, 2010
    Inventors: Mikio Fujiwara, Masahide Sasaki, Hiroshi Matsuo, Hirohisa Nagata
  • Patent number: 7403713
    Abstract: Quantum source coding apparatus for communication of quantum information comprising: a quantum state preparation device for converting input messages into block messages; a coding device for producing coded signals by compressing the block messages prepared by the quantum state preparation device; and an output device for outputting the coded signals produced by the coding device.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: July 22, 2008
    Assignees: University of Hertfordshire, National Institute of Information and Communications Technology, University of Strathelyde
    Inventors: Masahide Sasaki, Yasuyoshi Mitsumori, Atsushi Hasegawa, Masahiro Takeoka, John A. Vaccaro, Stephen M. Barnett, Erika Andersson
  • Patent number: 7176439
    Abstract: This invention provides a method for manufacturing a circuit for photon number counting without destroying a FET within the circuit by manufacturing a photodetector for weak light, the photodetector for weak light comprising a circuit on a substrate, the circuit comprising light detection means and a field effect transistor (FET), the method comprising: a light detection means connection step; an FET electrode-to-substrate electrode connection step; an external electrode connection step, a light detection means-to-gate connection step.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: February 13, 2007
    Assignee: National Institute of Information and Communication Technology
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Patent number: 7115868
    Abstract: The present invention provides a photodetector for weak light that can prevent noise from impurities, prevent electrodes from disconnecting from the substrate, and can be easily cooled; the present invention further provides a photodetector for weak light that can count the number of photons; the present invention solves the above problems by using an ultraviolet light transparent substrate on the photodetector for weak light.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: October 3, 2006
    Assignee: National Institute of Information and Communications Technology Incorporated Administrative Agency
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Patent number: 7078667
    Abstract: This invention provides a photodetector for weak light and a weak light detection system including the photodetector for weak light the photodetector for weak light is comprised of a substrate on which an integrating read circuit including a PIN photodiode or an APD and an FET is mounted, wherein the entire assembly is mounted while separating the substrate from a ground potential without grounding the substrate, such a photodetector for weak light can reduce noise and ensure a high enough sensitivity enough to be able to discriminate the number of photons.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: July 18, 2006
    Assignee: National Institute of Information and Communications Technology Incorporated Administrative Agency
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Patent number: 7067790
    Abstract: The present invention provides a photodetector for weak light that can release charge from the circuit without increasing capacity; the present invention being characterized by a photodetector for weak light that has a charge release means which permits the photodetector for weak light of the present invention to avoid increasing its capacity because it does not require a reset transistor integrated with the photodector, rather the charge reset means of the present invention lowers mounting capacity by removing itself from the circuit after it releases the charge.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: June 27, 2006
    Assignee: National Institute of Information and Communications Technology Incorporated Administrative Agency
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Publication number: 20050035274
    Abstract: This invention provides a photodetector for weak light and a weak light detection system including the photodetector for weak light the photodetector for weak light is comprised of a substrate on which an integrating read circuit including a PIN photodiode or an APD and an FET is mounted, wherein the entire assembly is mounted while separating the substrate from a ground potential without grounding the substrate, such a photodetector for weak light can reduce noise and ensure a high enough sensitivity enough to be able to discriminate the number of photons.
    Type: Application
    Filed: July 6, 2004
    Publication date: February 17, 2005
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Publication number: 20050029434
    Abstract: This invention provides a method for manufacturing a circuit for photon number counting without destroying a FET within the circuit by manufacturing a photodetector for weak light, the photodetector for weak light comprising a circuit on a substrate, the circuit comprising light detection means and a field effect transistor (FET), the method comprising: a light detection means connection step; an FET electrode-to-substrate electrode connection step; an external electrode connection step, a light detection means-to-gate connection step.
    Type: Application
    Filed: July 6, 2004
    Publication date: February 10, 2005
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Publication number: 20050023467
    Abstract: The present invention provides a photodetector for weak light that can prevent noise from impurities, prevent electrodes from disconnecting from the substrate, and can be easily cooled; the present invention further provides a photodetector for weak light that can count the number of photons; the present invention solves the above problems by using an ultraviolet light transparent substrate on the photodetector for weak light.
    Type: Application
    Filed: July 6, 2004
    Publication date: February 3, 2005
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Publication number: 20050023542
    Abstract: The present invention provides a photodetector for weak light that can release charge from the circuit without increasing capacity; the present invention being characterized by a photodetector for weak light that has a charge release means which permits the photodetector for weak light of the present invention to avoid increasing its capacity because it does not require a reset transistor integrated with the photodector, rather the charge reset means of the present invention lowers mounting capacity by removing itself from the circuit after it releases the charge.
    Type: Application
    Filed: July 6, 2004
    Publication date: February 3, 2005
    Inventors: Mikio Fujiwara, Masahide Sasaki, Makoto Akiba
  • Publication number: 20040234264
    Abstract: Quantum source coding apparatus for communication of quantum information comprising: a quantum state preparation device for converting input messages into block messages; a coding device for producing coded signals by compressing the block messages prepared by the quantum state preparation device; and an output device for outputting the coded signals produced by the coding device.
    Type: Application
    Filed: March 4, 2004
    Publication date: November 25, 2004
    Inventors: Masahide Sasaki, Yasuyoshi Mitsumori, Atsushi Hasegawa, Masahiro Takeoka, John A. Vaccaro, Stephen M. Barnett, Erika Andersson
  • Patent number: 6319725
    Abstract: The present invention provides a method of estimating ingredients of liquefaction products of coal or its analogues from a resonance spectrum thereof obtained using their solid state 13C nuclear magnetic resonance spectrometer. The method comprises the first step of obtaining a resonance spectrum of coal or its analogues using a solid state 13C nuclear magnetic resonance spectrometer, the second step of determining distribution of various types of carbon having different linkage types which constitute the molecular structure of the coal or its analogues, and the third step of estimating ingredients of liquefaction products of the coal or its analogues on the basis of the determined carbon distribution.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: November 20, 2001
    Assignee: Agency of Industrial Science and Technology
    Inventors: Ryoichi Yoshida, Tadashi Yoshida, Mitsuyoshi Yamamoto, Hiroshi Nagaishi, Masahide Sasaki