Patents by Inventor Yuji Nagai

Yuji Nagai 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).

  • Publication number: 20170271017
    Abstract: A semiconductor memory device according to an embodiment includes: a memory cell array including a plurality of memory cells that are NAND-connected; and a control circuit that executes a write sequence, the write sequence writing data to the memory cells, the write sequence including a plurality of write stages, one of the write stages applying to the memory cells a plurality of program pulses whose amplitudes increase by a certain increment, the write stages including 1st to Nth, where N is an integer of 2 or more, write stages, and an initial amplitude and the increment of the program pulse applied in the N?1th write stage being the same as an initial amplitude and the increment of the program pulse applied in the Nth write stage.
    Type: Application
    Filed: September 7, 2016
    Publication date: September 21, 2017
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yuki KANAMORI, Yuji NAGAI, Jun NAKAI, Kenri NAKAI
  • Publication number: 20170186484
    Abstract: According to one embodiment, a semiconductor storage apparatus includes a memory cell array and a read circuit. The memory cell array includes a memory cell which is connected to a word line. A threshold voltage of the memory cell corresponds to a data value of multiple bits. The read circuit receives designation of one bit among the multiple bits, applies a first reading voltage and a second reading voltage corresponding to the designated bit to the word line, senses ON or OFF of the memory cell for each reading voltage, and outputs a first sensed value and a second sensed value after performing the sensing for each reading voltage. The first sensed value is a sensing result in a case where the first reading voltage is applied. The second sensed value is a sensing result in a case where the second reading voltage is applied.
    Type: Application
    Filed: December 27, 2016
    Publication date: June 29, 2017
    Inventors: Marie TAKADA, Masanobu SHIRAKAWA, Yuji NAGAI
  • Patent number: 9620218
    Abstract: According to one embodiment, each memory chip included in a memory package includes a first storage unit that stores therein first information that is n-bit information and is a comparison target of a chip address, and is used for identifying its own memory chip, a second storage unit that stores therein second information for determining an effective bit of the n-bit first information, and a control unit that determines an effective bit of the n-bit first information and an effective bit of the chip address based on the second information.
    Type: Grant
    Filed: August 16, 2016
    Date of Patent: April 11, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshikazu Takeyama, Yuji Nagai
  • Patent number: 9544138
    Abstract: According to one embodiment, an authentication method between an authenticatee which stores key information having a data structure composed of a key transition record, secret information XY of a matrix form, and secret information XYE which is created by encrypting the secret information XY, and an authenticator which authenticates the authenticatee, includes selecting, by the authenticator, a record corresponding to a device index of the authenticator from the key information which is received from the authenticatee, and decrypting the record by a device key, thereby taking out a key transition, and executing, by the authenticator, a decryption process on the secret information XYE, which is received from the authenticatee, by using the corresponding key transition, and sharing the secret information XY.
    Type: Grant
    Filed: February 17, 2012
    Date of Patent: January 10, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuji Nagai, Taku Kato, Tatsuyuki Matsushita
  • Publication number: 20160358656
    Abstract: According to one embodiment, each memory chip included in a memory package includes a first storage unit that stores therein first information that is n-bit information and is a comparison target of a chip address, and is used for identifying its own memory chip, a second storage unit that stores therein second information for determining an effective bit of the n-bit first information, and a control unit that determines an effective bit of the n-bit first information and an effective bit of the chip address based on the second information.
    Type: Application
    Filed: August 16, 2016
    Publication date: December 8, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshikazu TAKEYAMA, Yuji NAGAI
  • Patent number: 9449193
    Abstract: According to one embodiment, an information processing apparatus includes a nonvolatile semiconductor memory and a processor. The nonvolatile semiconductor memory stores identification information. The processor controls an application which executes authentication processing for authenticating validation of the identification information stored in the nonvolatile semiconductor memory. The processor executes the application to read the identification information from the nonvolatile semiconductor memory, and to execute the authentication processing for determining whether or not the identification information is authentic. When the identification information is authentic, the processor continues at least some processes of the application, and when the identification information is inauthentic, the processor ends at least some processes of the application.
    Type: Grant
    Filed: February 25, 2014
    Date of Patent: September 20, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shinichi Matsukawa, Yasufumi Tsumagari, Yuji Nagai
  • Publication number: 20160267999
    Abstract: According to one embodiment, a semiconductor memory device includes: memory cells; word lines electrically connected to gates of the memory cell; and an interconnect electrically connected to one end of the memory cells. A first potential for applying to a selected memory cell in a read operation is determined based on a potential of the interconnect during sequentially increasing or decreasing a potential of the word line.
    Type: Application
    Filed: September 8, 2015
    Publication date: September 15, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshikazu TAKEYAMA, Yuji Nagai, Katsuaki Isobe
  • Patent number: 9443595
    Abstract: According to one embodiment, each memory chip included in a memory package includes a first storage unit that stores therein first information that is n-bit information and is a comparison target of a chip address, and is used for identifying its own memory chip, a second storage unit that stores therein second information for determining an effective bit of the n-bit first information, and a control unit that determines an effective bit of the n-bit first information and an effective bit of the chip address based on the second information.
    Type: Grant
    Filed: January 20, 2016
    Date of Patent: September 13, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshikazu Takeyama, Yuji Nagai
  • Patent number: 9418022
    Abstract: According to one embodiment, a storage system includes a host device, 2 storing medium. The secure storing medium includes: a memory provided with a protected first storing region which stores secret information sent from the host device, and a second storing region which stores encoded contents; and a controller which carries out authentication processing for accessing the first storing region. The host device and the secure storing medium produce a bus key which is shared only by the host device and the secure storing medium by authentication processing, and which is used for encoding processing when information of the first storing region is sent and received between the host device and the secure storing medium. The host device has the capability to request the secure storing medium to send a status.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: August 16, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuji Nagai, Yasufumi Tsumagari, Shinichi Matsukawa, Hiroyuki Sakamoto, Hideki Mimura
  • Patent number: 9413532
    Abstract: A controller is provided with a controller key and a first controller identification information unique to the controller. The controller generates a controller unique key unique to a respective controller based on the controller key and the first controller identification information, and a second controller identification information based on the first controller identification information. A decryptor decrypts the encrypted medium device key using the controller unique key to obtain a medium device key. An authentication/key exchange process unit performs authentication/key exchange process with the host device through an interface unit using the medium device key and the medium device key certificate to establish the secure channel.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: August 9, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Taku Kato, Yuji Nagai, Tatsuyuki Matsushita
  • Publication number: 20160141033
    Abstract: According to one embodiment, each memory chip included in a memory package includes a first storage unit that stores therein first information that is n-bit information and is a comparison target of a chip address, and is used for identifying its own memory chip, a second storage unit that stores therein second information for determining an effective bit of the n-bit first information, and a control unit that determines an effective bit of the n-bit first information and an effective bit of the chip address based on the second information.
    Type: Application
    Filed: January 20, 2016
    Publication date: May 19, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshikazu TAKEYAMA, Yuji NAGAI
  • Patent number: 9319389
    Abstract: A controller is provided with a controller key and a first controller identification information unique to the controller. The controller generates a controller unique key unique to a respective controller based on the controller key and the first controller identification information, and a second controller identification information based on the first controller identification information. A decryptor decrypts the encrypted medium device key using the controller unique key to obtain a medium device key. An authentication/key exchange process unit performs authentication/key exchange process with the host device through an interface unit using the medium device key, the medium device key certificate and the second controller identification information to establish a secure channel.
    Type: Grant
    Filed: June 2, 2014
    Date of Patent: April 19, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Taku Kato, Yuji Nagai, Tatsuyuki Matsushita
  • Patent number: 9294285
    Abstract: The data storage portion stores an encrypted medium device key Enc (Kcu, Kmd_i) generated by encrypting a medium device key (Kmd_i), a medium device key certificate (Certmedia), and encrypted content data generated by encrypting content data, the controller stores a controller key (Kc) and first controller identification information (IDcu), the information recording device being configured to execute, after being connected to an external host device, an one-way function calculation based on the controller key (Kc) and the first controller identification information (IDcu) to generate a controller unique key (Kcu) used when decrypting the encrypted medium device key Enc (Kcu, Kmd_i), and second controller identification information (IDcntr) used when decrypting the encrypted content data.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: March 22, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Taku Kato, Yuji Nagai, Tatsuyuki Matsushita
  • Publication number: 20160080147
    Abstract: According to one embodiment, an authenticator which authenticates an authenticatee, which stores first key information (NKey) that is hidden, includes a memory configured to store second key information (HKey) which is hidden, a random number generation module configured to generate random number information, and a data generation module configured to generate a session key (SKey) by using the second key information (HKey) and the random number information. The authenticator is configured such that the second key information (HKey) is generated from the first key information (NKey) but the first key information (NKey) is not generated from the second key information (HKey).
    Type: Application
    Filed: November 12, 2015
    Publication date: March 17, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Taku KATO, Tatsuyuki Matushita, Yuji Nagai, Fangming Zhao
  • Patent number: 9286960
    Abstract: According to one embodiment, each memory chip included in a memory package includes a first storage unit that stores therein first information that is n-bit information and is a comparison target of a chip address, and is used for identifying its own memory chip, a second storage unit that stores therein second information for determining an effective bit of the n-bit first information, and a control unit that determines an effective bit of the n-bit first information and an effective bit of the chip address based on the second information.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: March 15, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshikazu Takeyama, Yuji Nagai
  • Publication number: 20160045625
    Abstract: A compound selected from the group consisting of compounds represented by the formulas below or pharmaceutically acceptable salt thereof is useful in PET imaging for AMPA receptor.
    Type: Application
    Filed: April 2, 2014
    Publication date: February 18, 2016
    Inventors: Norihito Oi, Noboru Yamamoto, Michiyuki Suzuki, Yosuke Nakatani, Tetsuya Suhara, Meiei Cho, Toshimitsu Fukumura, Makoto Higuchi, Takafumi Minamimoto, Jun Maeda, Masaki Tokunaga, Yuji Nagai
  • Patent number: 9253169
    Abstract: According to one embodiment, a device includes a second data generator configured to generate a session key (SKey) by encrypting a random number (RN) with the second key (HKey) in AES operation; a one-way function processor configured to generate an authentication information (Oneway-ID) by processing the secret identification information (SecretID) with the session key (SKey) in one-way function operation; and a data output interface configured to output the encrypted secret identification information (E-SecretID) and the authentication information (Oneway-ID) to outside of the device.
    Type: Grant
    Filed: April 21, 2014
    Date of Patent: February 2, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuji Nagai, Taku Kato, Tatsuyuki Matsushita
  • Patent number: 9225513
    Abstract: According to one embodiment, an authenticator which authenticates an authenticatee, which stores first key information (NKey) that is hidden, includes a memory configured to store second key information (HKey) which is hidden, a random number generation module configured to generate random number information, and a data generation module configured to generate a session key (SKey) by using the second key information (HKey) and the random number information. The authenticator is configured such that the second key information (HKey) is generated from the first key information (NKey) but the first key information (NKey) is not generated from the second key information (HKey).
    Type: Grant
    Filed: November 26, 2013
    Date of Patent: December 29, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Taku Kato, Tatsuyuki Matsushita, Yuji Nagai, Fangming Zhao
  • Patent number: 9201811
    Abstract: According to one embodiment, an authentication method includes generating, by the memory, first authentication information by calculating secret identification information with a memory session key in one-way function operation, transmitting encrypted secret identification information, a family key block, and the first authentication information to a host, and generating, by the host, second authentication information by calculating the secret identification information generated by decrypting the encrypted secret identification information with the host session key in one-way function operation. The method further includes comparing, by the host, the first authentication information with the second authentication information.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: December 1, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuji Nagai, Taku Kato, Tatsuyuki Matsushita, Toshihiro Suzuki, Noboru Shibata
  • Publication number: 20150341345
    Abstract: A security system includes a controller manufacturer, a key issuer, and a medium manufacturer. The controller manufacturer writes a controller key Kc and a controller unique ID (IDcu) in the controller at the time of manufacturing the controller, and transmits the controller key Kc to the key issuer. The key issuer generates a medium device key Kmd_i and a medium device key certificate Certmedia, and encrypts the medium device key Kmd_i using the controller key Kc to generate encrypted medium device key Enc (Kc, Kmd_i). The medium manufacturer decrypts the encrypted medium device key Enc (Kc, Kmd_i) received from the key issuer, using the controller key Kc in the controller, and encrypts the medium device key Kmd_i obtained by decryption using a controller unique key Kcu generated from the controller unique ID (IDcu) in the controller, and then store it in a memory.
    Type: Application
    Filed: August 4, 2015
    Publication date: November 26, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuji NAGAI, Taku Kato, Tatsuyuki Matsushita, Shinichi Matsukawa, Yasufumi Tsumagari