Patents by Inventor Ririka TAKAHASHI

Ririka TAKAHASHI 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: 10439807
    Abstract: According to an embodiment, a communication device includes a receiver, an allocator, a first communication unit, an encryption processor, a second communication unit, and a controller. The receiver is configured to receive a shared key shared with another device. The allocator is configured to allocate the shared key to a transmission key or a reception key. The first communication unit is configured to receive data from an application. The encryption processor is configured to encrypt the data with the transmission key and decrypt the data encrypted by the other device with the reception key. The second communication unit is configured to communicate with the other device by using the encrypted data. The controller is configured to control at least one of allocation of the shared key, traffic of the first communication unit, and traffic of the second communication unit, by using state information of the device.
    Type: Grant
    Filed: February 15, 2017
    Date of Patent: October 8, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Ririka Takahashi
  • Patent number: 10348492
    Abstract: According to an embodiment, a quantum key distribution device includes first and second operation units. The first operation unit is configured to perform a first operation as a key distillation operation. The first operation unit includes a hardware circuit for performing a part of the first operation. The key distillation operation includes a sifting operation for a photon bit string generated through quantum key distribution with another quantum key distribution device via a quantum communication channel. The second operation unit is configured to perform a second operation as a key distillation operation other than the first operation. The second operation unit includes a circuit for a part of the second operation. The first operation unit stores intermediate data generated by the first operation. The second operation unit generates, by the second operation, a cryptographic key being the same as for the another quantum key distribution device from the intermediate data.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: July 9, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Kazuaki Doi, Ririka Takahashi, Akira Murakami
  • Patent number: 10341097
    Abstract: According to an embodiment, a communication device is connected with another communication device through a quantum communication channel with a shared encryption key. The device includes a communication unit, a sifter, a corrector, a calculator, and an extractor. The communication unit is configured to acquire a sequence of photons through the quantum communication channel and acquire a photon bit string corresponding to the sequence of photons. The sifter is configured to generate a shared bit string from the photon bit string by sifting processing using basis information. The corrector is configured to generate a corrected bit string by correcting an error included in the shared bit string. The calculator is configured to generate a hash-calculated bit string by performing hash calculation on the corrected bit string. The extractor is configured to extract, as the key, from the hash-calculated bit string, a bit string having the length of the key.
    Type: Grant
    Filed: December 19, 2016
    Date of Patent: July 2, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ririka Takahashi, Yoshimichi Tanizawa
  • Patent number: 10223182
    Abstract: According to an embodiment, a communication device is connected with external devices by quantum communication channels and a classical communication channel, and generates an encryption key with photons exchanged over the quantum communication channel. The communication device includes an acquirer, a calculator, a selector, and a communicating unit. The acquirer is configured to acquire a quantum error rate for each quantum communication channel. The calculator is configured to calculate a metric of a first path to each external device based on the quantum error rate. The selector is configured to select a second path in the classical communication channel to a specific one of the external devices based on the metric. The communicating unit is configured to transmit an application key to the specific one of the external devices over the second path.
    Type: Grant
    Filed: October 16, 2015
    Date of Patent: March 5, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Ririka Takahashi
  • Publication number: 20180255039
    Abstract: According to one embodiment, a key sharing device includes one or more processors function as a plurality of individual processing units. Each of the individual processing units performs any one of a plurality of individual processing operations included in processing that generates a cryptographic key by quantum key distribution. The cryptographic key is shared between the key sharing device and another key sharing device. The individual processing unit includes a control unit that controls execution of the corresponding individual processing operation according to a usage state of a storage that stores result information at least one of a result of an individual processing operation and identification information for identifying the result.
    Type: Application
    Filed: September 11, 2017
    Publication date: September 6, 2018
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Ririka TAKAHASHI, Yoshimichi Tanizawa
  • Patent number: 9928370
    Abstract: According to an embodiment, a communication device includes an acquirer and a determiner. The acquirer is configured to acquire a first history value for each of one or more applications that use an encryption key. The first history value indicates a history value of a volume of the encryption key used by the each of one or more applications. The determiner is configured to determine a volume of the encryption key to be assigned to the corresponding application, according to the first history value.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: March 27, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Ririka Takahashi, Shinichi Kawamura, Shinya Murai
  • Publication number: 20180054306
    Abstract: According to an embodiment, a communication device includes a receiver, an allocator, a first communication unit, an encryption processor, a second communication unit, and a controller. The receiver is configured to receive a shared key shared with another device. The allocator is configured to allocate the shared key to a transmission key or a reception key. The first communication unit is configured to receive data from an application. The encryption processor is configured to encrypt the data with the transmission key and decrypt the data encrypted by the other device with the reception key. The second communication unit is configured to communicate with the other device by using the encrypted data. The controller is configured to control at least one of allocation of the shared key, traffic of the first communication unit, and traffic of the second communication unit, by using state information of the device.
    Type: Application
    Filed: February 15, 2017
    Publication date: February 22, 2018
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi TANIZAWA, Ririka Takahashi
  • Patent number: 9768954
    Abstract: According to an embodiment, a quantum key distribution device includes a quantum key distributor, a sifter, a corrector, an identifier, a classifier, a calculator, and a privacy amplifier. The quantum key distributor obtains a photon string from a photon string of two or more intensities of light pulses. The sifter obtains pulse information indicating the light pulse to which each bit of a shared bit string corresponds. The corrector corrects an error included in the shared bit string and generates a post-correction bit string. The identifier generates error position information. The classifier classifies each bit of the post-correction bit string. The calculator calculates the error rate for each light pulse and each base using the error position information. The privacy amplifier generates a cryptographic key from the post-correction bit string on the basis of the error rate.
    Type: Grant
    Filed: September 21, 2015
    Date of Patent: September 19, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ririka Takahashi, Yoshimichi Tanizawa
  • Publication number: 20170264434
    Abstract: According to an embodiment, a communication device is connected with another communication device through a quantum communication channel with a shared encryption key. The device includes a communication unit, a sifter, a corrector, a calculator, and an extractor. The communication unit is configured to acquire a sequence of photons through the quantum communication channel and acquire a photon bit string corresponding to the sequence of photons. The sifter is configured to generate a shared bit string from the photon bit string by sifting processing using basis information. The corrector is configured to generate a corrected bit string by correcting an error included in the shared bit string. The calculator is configured to generate a hash-calculated bit string by performing hash calculation on the corrected bit string. The extractor is configured to extract, as the key, from the hash-calculated bit string, a bit string having the length of the key.
    Type: Application
    Filed: December 19, 2016
    Publication date: September 14, 2017
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Ririka TAKAHASHI, Yoshimichi Tanizawa
  • Patent number: 9509589
    Abstract: According to an embodiment, a communication device is connected to a first network and a second network. The communication device includes a generating unit and a converting unit. The generating unit is configured to generate a first set of route information that is route information of the first network. The converting unit is configured to convert the first set of route information, and generate a second set of route information that is route information of the second network.
    Type: Grant
    Filed: February 19, 2014
    Date of Patent: November 29, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Ririka Takahashi
  • Patent number: 9455827
    Abstract: According to an embodiment, a communication apparatus includes a cryptographic key storage, a transmitter, a receiver, and a sharing controller. The cryptographic key storage stores therein one or more cryptographic keys shared with an external device. The transmitter transmits specifying information that specifies at least one of the cryptographic keys to the external device. The receiver receives determination information that indicates a result of determination, which is made by the external device based on the specifying information, on whether the shared cryptographic key is consistent between the apparatus and the external device. When receiving the determination information indicating that the shared cryptographic key is inconsistent between the apparatus and the external device, the sharing controller deletes the cryptographic key specified by the specifying information from the cryptographic key storage.
    Type: Grant
    Filed: July 31, 2014
    Date of Patent: September 27, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Ririka Takahashi, Alex Dixon
  • Patent number: 9450929
    Abstract: According to an embodiment, a communication device is connected to a plurality of external devices which share key information with each other. The communication device includes a detector and an instructing unit. The detector is configured to, from among the external devices, detect an external device that has been subject to attack. The instructing unit is configured to issue an instruction to stop using key information which is shared with the detected external device.
    Type: Grant
    Filed: November 18, 2013
    Date of Patent: September 20, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Ririka Takahashi
  • Publication number: 20160218868
    Abstract: According to an embodiment, a quantum key distribution device includes a quantum key distributor, a sifter, a corrector, an identifier, a classifier, a calculator, and a privacy amplifier. The quantum key distributor obtains a photon string from a photon string of two or more intensities of light pulses. The sifter obtains pulse information indicating the light pulse to which each bit of a shared bit string corresponds. The corrector corrects an error included in the shared bit string and generates a post-correction bit string. The identifier generates error position information. The classifier classifies each bit of the post-correction bit string. The calculator calculates the error rate for each light pulse and each base using the error position information. The privacy amplifier generates a cryptographic key from the post-correction bit string on the basis of the error rate.
    Type: Application
    Filed: September 21, 2015
    Publication date: July 28, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Ririka TAKAHASHI, Yoshimichi TANIZAWA
  • Publication number: 20160197723
    Abstract: According to an embodiment, a communication device is connected with external devices by quantum communication channels and a classical communication channel, and generates an encryption key with photons exchanged over the quantum communication channel. The communication device includes an acquirer, a calculator, a selector, and a communicating unit. The acquirer is configured to acquire a quantum error rate for each quantum communication channel. The calculator is configured to calculate a metric of a first path to each external device based on the quantum error rate. The selector is configured to select a second path in the classical communication channel to a specific one of the external devices based on the metric. The communicating unit is configured to transmit an application key to the specific one of the external devices over the second path.
    Type: Application
    Filed: October 16, 2015
    Publication date: July 7, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Ririka TAKAHASHI
  • Patent number: 9356780
    Abstract: A communication device assigns a key taking the degree of priority of applications into account in a case where a key generation/sharing system in which a plurality of applications are connected to a node is not able to realize key assignment that satisfies the key rates requested by the plurality of applications. For example, the device realizes a method of assigning an application key that takes the degree of priority into account according to which control is performed in such a way that the key rate requested by an important application is preferentially satisfied.
    Type: Grant
    Filed: February 25, 2014
    Date of Patent: May 31, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Ririka Takahashi, Shinichi Kawamura, Shinya Murai
  • Patent number: 9350542
    Abstract: According to an embodiment, a quantum key distribution (QKD) device includes a sharing unit, a correcting unit, a deciding unit, a calculator, and a privacy amplifier. The sharing unit is configured to generate a shared bit string through quantum key distribution with each other QKD device connected via quantum communication channels. The correcting unit is configured to generate a corrected bit string through an error correction process on the shared bit string. The deciding unit is configured to calculate an error rate in the corresponding quantum communication channel with respect to each other QKD device, and decide on a combined error rate from error rates calculated. The calculator is configured to calculate, based on the combined error rate, a length of an encryption key to be shared. The privacy amplifier is configured to generate the encryption key having the calculated length of the encryption key from the corrected bit string.
    Type: Grant
    Filed: January 26, 2015
    Date of Patent: May 24, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ririka Takahashi, Yoshimichi Tanizawa
  • Publication number: 20160142203
    Abstract: According to an embodiment, a quantum key distribution device includes first and second operation units. The first operation unit is configured to perform a first operation as a key distillation operation. The first operation unit includes a hardware circuit for performing a part of the first operation. The key distillation operation includes a sifting operation for a photon bit string generated through quantum key distribution with another quantum key distribution device via a quantum communication channel. The second operation unit is configured to perform a second operation as a key distillation operation other than the first operation. The second operation unit includes a circuit for a part of the second operation. The first operation unit stores intermediate data generated by the first operation. The second operation unit generates, by the second operation, a cryptographic key being the same as for the another quantum key distribution device from the intermediate data.
    Type: Application
    Filed: September 30, 2015
    Publication date: May 19, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi TANIZAWA, Hideaki SATO, Kazuaki DOI, Ririka TAKAHASHI, Akira MURAKAMI
  • Publication number: 20150215122
    Abstract: According to an embodiment, a quantum key distribution (QKD) device includes a sharing unit, a correcting unit, a deciding unit, a calculator, and a privacy amplifier. The sharing unit is configured to generate a shared bit string through quantum key distribution with each other QKD device connected via quantum communication channels. The correcting unit is configured to generate a corrected bit string through an error correction process on the shared bit string. The deciding unit is configured to calculate an error rate in the corresponding quantum communication channel with respect to each other QKD device, and decide on a combined error rate from error rates calculated. The calculator is configured to calculate, based on the combined error rate, a length of an encryption key to be shared. The privacy amplifier is configured to generate the encryption key having the calculated length of the encryption key from the corrected bit string.
    Type: Application
    Filed: January 26, 2015
    Publication date: July 30, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Ririka TAKAHASHI, Yoshimichi TANIZAWA
  • Publication number: 20150036825
    Abstract: According to an embodiment, a communication apparatus includes a cryptographic key storage, a transmitter, a receiver, and a sharing controller. The cryptographic key storage stores therein one or more cryptographic keys shared with an external device. The transmitter transmits specifying information that specifies at least one of the cryptographic keys to the external device. The receiver receives determination information that indicates a result of determination, which is made by the external device based on the specifying information, on whether the shared cryptographic key is consistent between the apparatus and the external device. When receiving the determination information indicating that the shared cryptographic key is inconsistent between the apparatus and the external device, the sharing controller deletes the cryptographic key specified by the specifying information from the cryptographic key storage.
    Type: Application
    Filed: July 31, 2014
    Publication date: February 5, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi TANIZAWA, Hideaki SATO, Ririka TAKAHASHI, Alex DIXON
  • Publication number: 20140365786
    Abstract: According to an embodiment, a communication device includes an acquirer and a determiner. The acquirer is configured to acquire a first history value for each of one or more applications that use an encryption key. The first history value indicates a history value of a volume of the encryption key used by the each of one or more applications. The determiner is configured to determine a volume of the encryption key to be assigned to the corresponding application, according to the first history value.
    Type: Application
    Filed: February 20, 2014
    Publication date: December 11, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshimichi Tanizawa, Hideaki Sato, Ririka Takahashi, Shinichi Kawamura, Shinya Murai