Patents by Inventor Masahiko Takenaka

Masahiko Takenaka 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: 8369516
    Abstract: A common key block encryption apparatus for performing a nonlinear transformation with a multiplication executed in a binary field or a composite field includes a computing unit to execute a computation other than the nonlinear transformation with fixed value masked input data obtained by XORing input data with a fixed mask value, an XOR operation circuit to transform all input data into fixed value masked input data by XORing the input data with a fixed mask value and to transform the data into random value masked input data by XORing the input data with a random mask value in the multiplication, a multiplier to execute a multiplication based on the random value masked input data output from the XOR operation circuit, and a random value mask-to-fixed mask value transformation circuit to again transform the random value masked output data into fixed value masked output data and to output the data.
    Type: Grant
    Filed: September 23, 2010
    Date of Patent: February 5, 2013
    Assignee: Fujitsu Limited
    Inventors: Kouichi Itoh, Souichi Okada, Masahiko Takenaka
  • Patent number: 8352529
    Abstract: REDC (A*B) is calculated for the values A and B by using a Montgomery's algorithm REDC. The part related to the A*B is performed by the three-input two-output product-sum calculation circuit. One digit ai of the value A, one digit bj of the value B and a carry value c1 are input to the product-sum calculation circuit, and ai*bj+c1 is calculated thereat. The higher-order digit of the r-adic two-digit of the calculation result is used as the carry value c1, and the lower digit is used for a later calculation. Further, one digit ni of a modulo N for the REDC, a predetermined value m and a carry value c2 are input into the product-sum calculation circuit, and n*ni+c2 is calculated thereat. The higher-order digit is used as the carry value c2, and the lower digit is used for a later calculation.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: January 8, 2013
    Assignee: Fujitsu Limited
    Inventors: Kazuyoshi Furukawa, Masahiko Takenaka
  • Patent number: 8335922
    Abstract: Certification/verification of authenticity and integrity of a digital document can be achieved, using meta information and content information and third-party certification thereof is achieved.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: December 18, 2012
    Assignee: Fujitsu Limited
    Inventors: Takashi Yoshioka, Masahiko Takenaka, Tetsuya Izu
  • Publication number: 20120317420
    Abstract: An electronic signature device includes a processor configured to internally execute signature generation processing of generating an electronic signature for a digital data string; and an output unit configured to output the digital data string and the generated electronic signature.
    Type: Application
    Filed: August 22, 2012
    Publication date: December 13, 2012
    Applicants: FUJITSU ADVANED ENGINEERING LIMITED, FUJITSU LIMITED
    Inventors: Fumitsugu MATSUO, Yousuke Harano, Masahiko Takenaka, Takashi Yoshioka, Fumiaki Chiba
  • Patent number: 8327156
    Abstract: A cryptographic processing device, comprising: a storage unit; initial setting unit for setting a value to be stored in the storage unit; Montgomery modular multiplication operation unit for performing a Montgomery modular multiplication operation plural times for a value set by the initial setting unit; and fault attack detection unit for determining whether or not a fault attack occurred for each of at least some parts of the Montgomery modular multiplication operations performed plural times.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: December 4, 2012
    Assignee: Fujitsu Limited
    Inventors: Kazuyoshi Furukawa, Kouichi Itoh, Masahiko Takenaka
  • Patent number: 8312266
    Abstract: A computer extracts the header information from an electronic mail, including an originality guarantee. The computer generates a header characterization for the header information subject to originality guarantee, and extracts message body information from the electronic mail and generates a body characterization for the message body information as well. The generated characterization set applies the header characterization and the body characterization, combined. The verification information is added to the generated characterization set for applying a signature, and characterization set is linked to electronic mail.
    Type: Grant
    Filed: July 2, 2008
    Date of Patent: November 13, 2012
    Assignee: Fujitsu Limited
    Inventors: Takashi Yoshioka, Masahiko Takenaka, Tetsuya Izu
  • Patent number: 8223968
    Abstract: An image data verification system for verifying image data using a computer and method are provided. The method includes registering image data of an original and extracting information regarding a part of information forming the original image data. The method also includes generating a feature value of the partial information and generating signature information.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: July 17, 2012
    Assignee: Fujitsu Limited
    Inventors: Takashi Yoshioka, Masahiko Takenaka
  • Patent number: 8218762
    Abstract: The first route selection device re-arrays a plurality of extended key mask values at random according to the value of a random number generated by a random number generation device. An extended key operation device generates an exclusive logical OR of a plurality of the re-arrayed extended key mask values, a data string representing extended key and an input data string. The second route selection device re-arrays the data string of the exclusive logical OR by performing a re-array conversely with the first route selection device according to the value of the random number. A non-linear conversion device applies non-linear conversion to the re-arrayed data string and outputs a data string masked by a plurality of non-linear conversion mask values. The third route selection device re-arrays the masked data string by performing the same re-array as the first route selection device according to the value of the random number.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: July 10, 2012
    Assignee: Fujitsu Limited
    Inventors: Kouichi Itoh, Souichi Okada, Masahiko Takenaka
  • Patent number: 8205077
    Abstract: A management apparatus comprising memory to store owner information, dependence relationship information, and authorized user information are associated with file information identifying the secret file, an authorized user determination unit to determine whether a source user of the browse request is registered as the authorized user of the browse request file, a dependent file specifying unit to specify a dependent file having a dependence relationship with the browse request file by referring to the dependence relationship information when the source user is authorized; and a browse permission response transmitting unit to transmit the browse permission response to the source user based on whether or not the source user is registered as the authorized user of the dependent file by referring to the authorized user information.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: June 19, 2012
    Assignee: Fujitsu Limited
    Inventors: Bintatsu Noda, Masahiko Takenaka, Takayuki Hasebe, Takeaki Terada, Takashi Yoshioka
  • Publication number: 20120118659
    Abstract: In an electrically-operated vehicle including rear wheels on right and left sides of a rear portion of a vehicle body, the electrically-operated vehicle includes a motor that drives the rear wheels, a battery 51 that is arranged above the motor, and a lower battery that is placed between the right and left rear wheels. The lower battery and the motor are arranged in a distributed manner over an axle of the rear wheels between a vehicle front side of the axle of the rear wheels and a vehicle rear side of the axle of the rear wheels. An upper end portion of a rear cushion is supported on a vehicle body frame, and the battery and the motor are supported on a lower end of the rear cushion.
    Type: Application
    Filed: November 4, 2011
    Publication date: May 17, 2012
    Applicant: HONDA MOTOR CO., LTD.
    Inventors: Yasuo Shinde, Nobuo Nakai, Masahiko Takenaka
  • Publication number: 20120008782
    Abstract: A data processing apparatus includes an address bus, a scramble unit, and a data bus. The address bus outputs address data to be given to a memory apparatus. The scramble unit scrambles write-in data into a storage position in the memory apparatus identified by the address data to obtain confidential data. The data bus outputs the confidential data. The scramble unit includes a first scrambler, a first converter and a second scrambler. The first scrambler XORs first mask data corresponding to the address data and the write-in data for each bit and makes it first scrambled data. The first converter performs one-to-one substitution conversion of the first scrambled data. The second scrambler XORs second mask data corresponding to the address data and data after the conversion of the first scrambled data by the first converter and outputs obtained second scrambled data as the confidential data.
    Type: Application
    Filed: September 20, 2011
    Publication date: January 12, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Kazuyoshi FURUKAWA, Takeshi Shimoyama, Masahiko Takenaka
  • Patent number: 8091015
    Abstract: A digital document management system is capable of guaranteeing that a partial correction has been made according to a proper procedure and achieving a third-party certification of the validity of the guarantee. The digital document management system manages document information created in a digital form, and includes partial identification information generation section that generates partial identification information that represents, in an identifiable manner, respective parts of the document information. A partial correction information generation section generates partial correction information which is information related to a correction history of a corrected part in the case where any correction has been required for the document information; and an original document information management section manages the document information, partial identification information, partial correction information, and prescribed policy information in an associated manner.
    Type: Grant
    Filed: October 18, 2006
    Date of Patent: January 3, 2012
    Assignee: Fujitsu Limited
    Inventors: Takashi Yoshioka, Masahiko Takenaka
  • Publication number: 20110314291
    Abstract: When input data (f0) is read into a digital signature generating apparatus, a hash value (h0) is calculated. The hash value (h0) is stored to a storage area (M1), which has the highest priority rank among 5 storage areas. Subsequently, when input data (f1) is read in, a hash value (h1) is calculated. Since the storage area (M1) is already occupied by the hash value (h0), the hash value (h0) is read out from storage area (M1), emptying the storage area (M1). The read hash value (h0) and the hash value (h1) are concatenated, forming a concatenated hash value (h0|h1) and a hash value (h0,1) is calculated. The hash value (h0,1) is stored to a storage area (M2), which has the highest priority rank after the storage area (M1). When input data (f2) is read in, a hash value (h2) is calculated and stored to the storage area (M1).
    Type: Application
    Filed: August 24, 2011
    Publication date: December 22, 2011
    Applicants: FUJITSU ADVANCED ENGINEERING LIMITED, FUJITSU LIMITED
    Inventors: Masahiko Takenaka, Takashi Yoshioka, Fumitsugu Matsuo, Fumiaki Chiba
  • Patent number: 8078661
    Abstract: A multiple-word multiplication-accumulation circuit suitable for use with a single-port memory. The circuit is composed of a multiplication-accumulation (MAC) operator and surrounding registers. The MAC operator has multiplicand and multiplier input ports with different bit widths to calculate a sum of products of multiple-word data read out of a memory. The registers serve as buffer storage of multiple-word data to be supplied to individual input ports of the MAC operator. The amount of data supplied to the MAC operator in each clock cycle is adjusted such that total amount of data consumed and produced by the MAC operator in one clock cycle will be equal to or smaller than the maximum amount of data that the memory can transfer in one clock cycle. This feature enables the use of a bandwidth-limited single-port memory, without causing adverse effect on the efficiency of MAC operator usage.
    Type: Grant
    Filed: July 26, 2004
    Date of Patent: December 13, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Kenji Mukaida, Masahiko Takenaka, Naoya Torii, Shoichi Masui
  • Patent number: 8037312
    Abstract: An apparatus for digital signature authentication includes a dividing unit that divides streaming data into plural pieces of partial data in a predetermined unit; a first creating unit that creates a hash value string including plural hash values corresponding to the pieces of partial data; a second creating unit that creates a first binary tree using the hash value string; and a third creating unit that creates a digital signature of a signer using a root value of the first binary tree.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: October 11, 2011
    Assignee: Fujitsu Limited
    Inventors: Masahiko Takenaka, Tetsuya Izu, Takashi Yoshioka
  • Patent number: 8035488
    Abstract: An information access system comprises a reader/writer for continually transmitting an ID request signal at a first frequency and being continuously ready to receive an RF signal at a second frequency, and an active contactless information storage device having a receiver for sensing a carrier of an RF signal at the first frequency, and a transmitter for transmitting a response signal at the second frequency when the ID request signal is received. When the receiver senses a carrier of an RF signal at the first frequency in a particular predetermined period, the receiver receives further the ID request signal, and, in response to the ID request signal, the transmitter transmits a response signal at the second frequency carrying an ID of the storage device stored. In the carrier sensing, the controller causes the receiver to be in an active state and the transmitter to be in an inactive state in the predetermined periods.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: October 11, 2011
    Assignee: Fujitsu Limited
    Inventors: Shinichi Shiotsu, Isamu Yamada, Satoshi Inano, Kouichi Yasaki, Akira Itasaki, Atsushi Sakai, Masahiko Takenaka, Takanao Ochiai
  • Patent number: 8032921
    Abstract: A first access policy is stored to provide information on a first distributee to which an electronic document is distributed, to which the first distributee is permitted to distribute the electronic document, and use rights that permit the second distributees to use the electronic document. Also stored is a distribution target information indicating the second distributees. When the first distributee requests permission to grant use rights to a specific distributee, the distribution target is consulted to confirm whether or not the specific distributee is included in the second distributees. A second access policy associating the specific distributee with the information on the use rights is then registered. When the specific distributee requests permission to use the electronic document, the second access policy is consulted to permit the specific distributee to use the electronic document.
    Type: Grant
    Filed: November 9, 2006
    Date of Patent: October 4, 2011
    Assignee: Fujitsu Limited
    Inventors: Masahiko Takenaka, Souichi Okada, Takashi Yoshioka, Bintatsu Noda
  • Patent number: 8003903
    Abstract: On a pivot bolt which rotatably and pivotally supports a side stand bar on a vehicle-body-side bracket, a switch unit which is constituted of a base and a rotary made of a resin and detects a rotational position of the side stand bar is mounted. A first engaging mechanism which is constituted of a groove and a projection is arranged between a cylindrical portion formed on the rotary and an engaging shaft and, at the same time, a second engaging mechanism which is constituted of a groove and a projection is arranged between the base and the cylindrical portion. The rotary on which a movable contact formed of a leaf spring is mounted allows a positioning pin which is formed on one end portion thereof to be engaged with a pin hole formed in a pivot portion and hence, the rotary is integrally rotated with the side stand bar.
    Type: Grant
    Filed: December 20, 2006
    Date of Patent: August 23, 2011
    Assignee: Honda Motor Co., Ltd.
    Inventors: Yoshihiro Nakazawa, Takashi Sumada, Hiroyuki Nakajima, Masahiko Takenaka, Shujiro Inui
  • Publication number: 20110194693
    Abstract: A cryptographic processing apparatus that encrypts plaintext using a fixed-value common key that is shared with other cryptographic processing apparatus, includes an acquiring unit that acquires random information being used within the cryptographic processing apparatuses, an encrypting unit that encrypts encryption target data using key information and outputs encrypted data when the encryption target data and the key information is set, a transmitting unit that transmits, to the other cryptographic processing apparatus, the encrypted data; and a setting unit that sets the fixed-value common key as the key information and the random information as the encryption target data when the random information is acquired by the acquiring unit, and sets the encrypted data as the key information and at least one portion of the plaintext as the target data when the encrypted data is acquired.
    Type: Application
    Filed: January 19, 2011
    Publication date: August 11, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Tetsuya IZU, Masahiko Takenaka
  • Patent number: 7971673
    Abstract: A saddle-ride type electric vehicle includes an electric motor for generates power for rotationally driving a rear wheel. Foot rests are provided for an occupant seated on an occupant seat. A battery is disposed in a space S surrounded by a down frame which is coupled to a head pipe or to a front end of a main frame and which extends downwardly, pivot frames, and the main frame. Steps disposed to both sides of the battery in planar view are provided to front ends of a pair of left and right step frames coupled to lower portion of the pivot frames, the step frames extending forward and overlapping a rear portion of the battery in planar view. The battery is wider in an area adjacent to the head pipe as compared to the width of the battery in an area adjacent to the steps.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: July 5, 2011
    Assignee: Honda Motor Co., Ltd.
    Inventors: Taiki Sasage, Masahiko Takenaka