Patents by Inventor Koichi Fujisaki

Koichi Fujisaki 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: 20110311048
    Abstract: According to one embodiment, the cryptographic operation apparatus performs a cryptographic operation using first and second key data and includes an initial mask value creating unit that creates the initial mask value using the second key data and data information. In addition, the cryptographic operation apparatus further includes a mask value updating unit that creates the mask value using the initial mask value and a mask value storing unit that stores and outputs the initial mask value and the created mask value. In addition, the encryption is performed using the input data, the first key data, and the output mask value.
    Type: Application
    Filed: June 13, 2011
    Publication date: December 22, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yuki NAGATA, Koichi Fujisaki
  • Publication number: 20110302418
    Abstract: One embodiment is an information processing device for obtaining an HMAC, including a padding circuit for generating first key data by adding a first constant with respect to secret key data when a secret key length of input secret key data is shorter than a block length of a hash function, setting the secret key data as second key data when the secret key length is equal to the block length, generating third key data by adding the first constant with respect to a first digest value when the secret key length is longer than the block length, and performing an exclusive OR operation with a second constant with respect to one of the first key data, the second key data, or the third key data to calculate first data; a hash calculation circuit for obtaining the first digest value and obtaining a second digest value; and a control unit for managing a processing state for calculating the HMAC, wherein the hash calculation circuit outputs a first midway progress value when interrupting a calculation process of the f
    Type: Application
    Filed: March 17, 2011
    Publication date: December 8, 2011
    Inventor: Koichi FUJISAKI
  • Publication number: 20110268266
    Abstract: According to one embodiment, a cryptographic processing apparatus is provided with first to fifth units. The first unit mask-converts input data from first temporary mask into first fixed mask (an invariable value in a first linear operation). In an encryption, the third unit performs a nonlinear operation on the mask-converted data and outputs a first result masked with second fixed mask data (an invariable value in a second linear operation). The fourth unit performs the second linear operation and outputs a encryption result masked with second fixed mask data. In a decryption, the second unit performs the first linear operation on the mask-converted data and outputs a second result masked with the first fixed mask. The third unit performs the nonlinear operation and outputs a decryption result masked with the second fixed mask. In encryption/decryptions, the fifth unit converts the mask of the encryption/decryption results into second temporary mask.
    Type: Application
    Filed: June 8, 2011
    Publication date: November 3, 2011
    Inventors: Koichi Fujisaki, Atsushi Shimbo
  • Publication number: 20110246791
    Abstract: According to one embodiment, a memory chip, which is connected to a writing device that writes data and to a reading device that reads data, includes: a memory including a first area that is a predetermined data storage area; a second encryption key generating unit that receives second key information stored in the reading device and generates a third key; and a sending unit that transmits, to the reading device, second encrypted data obtained by encrypting data stored in the memory using the third key. The second encrypted data is received by the reading device and is decrypted by using a fourth key that is stored in the reading device and that corresponds to the third key.
    Type: Application
    Filed: September 13, 2010
    Publication date: October 6, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toru Kambayashi, Taku Kato, Hiroshi Sukegawa, Yoshihiko Hirose, Koichi Fujisaki
  • Patent number: 8023643
    Abstract: A first Exclusive OR circuit operates an Exclusive OR between input data and a predetermined random number. An operation circuit performs one operation of encryption and decryption of output data from the first Exclusive OR circuit. A data register circuit, which has a plurality of data hold units, holds data from the operation circuit in one data hold unit of the plurality of data hold units in response to a selection signal, and supplies the data from the one data hold unit to the operation circuit. A second Exclusive OR circuit performs an Exclusive OR between output data from the data register circuit and the random number. The operation circuit recursively performs the one operation of the data from the data register circuit and outputs next data to the data register circuit.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: September 20, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Fujisaki, Hideo Shimizu, Atsushi Shimbo
  • Publication number: 20110140776
    Abstract: A variable frequency amplifier includes a main amplifier system 4 for amplifying one of signals into which an input signal is split by a directional coupler 3 to output the amplified signal, and an injection amplifier system 9 for adjusting at least one of the amplitude and phase of the other one of the signals into which the input signal is split by the directional coupler 3 according to a setting provided thereto from outside the variable frequency amplifier, and for amplifying the other signal and injecting this amplified signal into an output side of the main amplifier system 4.
    Type: Application
    Filed: November 4, 2009
    Publication date: June 16, 2011
    Applicant: Mitsubishi Electric Coporation
    Inventors: Kazuhisa Yamauchi, Hidenori Yukawa, Akira Inoue, Atsushi Yamamoto, Koichi Fujisaki, Hiroomi Ueda
  • Publication number: 20110131470
    Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.
    Type: Application
    Filed: September 15, 2010
    Publication date: June 2, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru KAMBAYASHI, Akihiro KASAHARA, Shinichi MATSUKAWA, Hiroyuki SAKAMOTO, Taku KATO, Hiroshi SUKEGAWA, Yoshihiko HIROSE, Atsushi SHIMBO, Koichi FUJISAKI
  • Patent number: 7920699
    Abstract: Valid code data and invalid code data are alternately input to a register that fetches data synchronously with a clock signal. A state of a data value input to the register is monitored. Each time when it is determined that the data is stabilized by the valid code data, the register holds the valid code data.
    Type: Grant
    Filed: July 14, 2008
    Date of Patent: April 5, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Fujisaki, Hideyuki Miyake
  • Patent number: 7893770
    Abstract: Provided is a power amplification device including: a DC power supply that outputs a drain voltage; a Doherty amplifier including a carrier amplifier and a peak amplifier, which are connected in parallel, and amplifies an RF signal; a voltage control circuit that outputs a first instruction to output a low voltage when an output power is equal to or lower than a given value, and outputs a second instruction to output a high voltage when the output power is larger than the given value; and a voltage converter circuit that converts the drain voltage to a voltage lower than the drain voltage and applies the converted voltage to drain terminals of the carrier amplifier and the peak amplifier according to the first instruction, and applies the drain voltage directly to the drain terminals of the carrier amplifier and the peak amplifier according to the second instruction.
    Type: Grant
    Filed: December 5, 2007
    Date of Patent: February 22, 2011
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kazuhisa Yamauchi, Yuji Sakai, Koichi Fujisaki, Akira Inoue
  • Patent number: 7869592
    Abstract: A calculation apparatus capable of executing any of a first calculating process operation including a first matrix calculation, and a second calculating process operation including a second matrix calculation, includes: a first calculation unit for executing the second matrix calculation; at least one calculation unit other than the first calculation unit, for executing a matrix calculation in parallel to the first calculation unit so as to execute the first matrix calculation; and a logic circuit for performing a logic calculation with respect to a calculation result of the first calculation unit and a calculation result of the other calculation unit. Then, when a calculation result of the first matrix calculation is requested, the calculation apparatus acquires the calculation result from the logic circuit.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: January 11, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Fujisaki, Atsushi Shimbo
  • Patent number: 7824451
    Abstract: The present invention provides a blue dye mixture which contains the pigments represented by formulae [1], [2], [3], and [4] The present invention also relates to dye mixtures in which there are compounded therewith a yellow dye mixture and/or a red dye mixture. The invention further relates to a method of dyeing polyester-based fibers and dyed polyester-based fibers and dyed polyester-based fiber materials.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: November 2, 2010
    Assignee: DyStar Textilfarben GmbH & Co. Deutschland KG
    Inventors: Toshio Hihara, Wataru Seto, Koichi Fujisaki, Daisuke Hosoda, Hiroshi Inoue
  • Patent number: 7761662
    Abstract: A cache controller is connected to a processor and a main memory. The cache controller is also connected to a cache memory that can read and write at a speed higher than the main memory. The cache memory is provided with a plurality of cache lines that include a tag area storing an address on the main memory, a capacity area storing a capacity value of a cache block, and a cache block. When a read request is executed from the processor to the main memory, the cache controller checks whether the requested data is present in the cache memory or not. A cache capacity determination unit determines a capacity value for the cache block and supplies to a capacity area.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: July 20, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Fujisaki, Hideo Shimizu
  • Publication number: 20100079210
    Abstract: Provided is a power amplification device including: a DC power supply that outputs a drain voltage; a Doherty amplifier including a carrier amplifier and a peak amplifier, which are connected in parallel, and amplifies an RF signal; a voltage control circuit that outputs a first instruction to output a low voltage when an output power is equal to or lower than a given value, and outputs a second instruction to output a high voltage when the output power is larger than the given value; and a voltage converter circuit that converts the drain voltage to a voltage lower than the drain voltage and applies the converted voltage to drain terminals of the carrier amplifier and the peak amplifier according to the first instruction, and applies the drain voltage directly to the drain terminals of the carrier amplifier and the peak amplifier according to the second instruction.
    Type: Application
    Filed: December 5, 2007
    Publication date: April 1, 2010
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kazuhisa Yamauchi, Yuji Sakai, Koichi Fujisaki, Akira Inoue
  • Patent number: 7653855
    Abstract: A random number test circuit includes a counting unit to count number of repetitions of a certain-value bit in a random number sequence, the repetitions occurring in series, a detecting unit to detect a plurality of numbers corresponding to a kind of bits in the random number sequence, and a determining unit to determine whether the random number sequence is normal, based on the numbers.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: January 26, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinichi Yasuda, Shinobu Fujita, Koichi Fujisaki, Tetsufumi Tanamoto, Keiko Abe
  • Publication number: 20090100226
    Abstract: A cache controller is connected to a processor and a main memory. The cache controller is also connected to a cache memory that can read and write at a speed higher than the main memory. The cache memory is provided with a plurality of cache lines that include a tag area storing an address on the main memory, a capacity area storing a capacity value of a cache block, and a cache block. When a read request is executed from the processor to the main memory, the cache controller checks whether the requested data is present in the cache memory or not. A cache capacity determination unit determines a capacity value for the cache block and supplies to a capacity area.
    Type: Application
    Filed: December 10, 2008
    Publication date: April 16, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Koichi Fujisaki, Hideo Shimizu
  • Publication number: 20090092246
    Abstract: A calculation apparatus capable of executing any of a first calculating process operation including a first matrix calculation, and a second calculating process operation including a second matrix calculation, includes: a first calculation unit for executing the second matrix calculation; at least one calculation unit other than the first calculation unit, for executing a matrix calculation in parallel to the first calculation unit so as to execute the first matrix calculation; and a logic circuit for performing a logic calculation with respect to a calculation result of the first calculation unit and a calculation result of the other calculation unit. Then, when a calculation result of the first matrix calculation is requested, the calculation apparatus acquires the calculation result from the logic circuit.
    Type: Application
    Filed: September 29, 2008
    Publication date: April 9, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koichi Fujisaki, Atsushi Shimbo
  • Publication number: 20090086962
    Abstract: Valid code data and invalid code data are alternately input to a register that fetches data synchronously with a clock signal. A state of a data value input to the register is monitored. Each time when it is determined that the data is stabilized by the valid code data, the register holds the valid code data.
    Type: Application
    Filed: July 14, 2008
    Publication date: April 2, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koichi Fujisaki, Hideyuki Miyake
  • Patent number: 7480777
    Abstract: A cache controller is connected to a processor and a main memory. The cache controller is also connected to a cache memory that can read and write at a speed higher than the main memory. The cache memory is provided with a plurality of cache lines that include a tag area storing an address on the main memory, a capacity area storing a capacity value of a cache block, and a cache block. When a read request is executed from the processor to the main memory, the cache controller checks whether the requested data is present in the cache memory or not. A cache capacity determination unit determines a capacity value for the cache block and supplies to a capacity area.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: January 20, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Fujisaki, Hideo Shimizu
  • Publication number: 20080292100
    Abstract: According to an aspect of the present invention, there is provided a non-linear data converter including: first to fourth converters that each performs a respective converting process on an input bit string to output respective output bit string; a generator that generates a random number bit string; and a selector that selects any one of the output bit strings from the first to fourth converters based on the random number bit string. Each of the converting processes is equivalent to performing a first mask process, a non-linear conversion predetermined for an encoding or a decoding and a second mask process.
    Type: Application
    Filed: March 21, 2008
    Publication date: November 27, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuichi KOMANO, Hideo Shimizu, Koichi Fujisaki, Hideyuki Miyake, Atsushi Shimbo
  • Publication number: 20080046790
    Abstract: A random number test circuit includes a counting unit to count number of repetitions of a certain-value bit in a random number sequence, the repetitions occurring in series, a detecting unit to detect a plurality of numbers corresponding to a kind of bits in the random number sequence, and a determining unit to determine whether the random number sequence is normal, based on the numbers.
    Type: Application
    Filed: October 19, 2007
    Publication date: February 21, 2008
    Inventors: Shinichi Yasuda, Shinobu Fujita, Koichi Fujisaki, Tetsufumi Tanamoto, Keiko Abe