Patents by Inventor Takeshi Shimoyama

Takeshi Shimoyama 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: 10129028
    Abstract: A method of equality verification using relational encryption including receiving a relational key that includes a first relational key component and a registration ciphertext that includes an encryption of a first plaintext data set. The method includes storing the registration ciphertext without decrypting the registration ciphertext. After the storing of the registration ciphertext, the method includes receiving an authentication request and communicating a safeguard data set that includes a random challenge in response to the authentication request. The method includes receiving an encrypted response that is generated based on the safeguard data set and a second plaintext data set. The method includes verifying a relationship between the encrypted response and the registration ciphertext using the relational key without decrypting the encrypted response and without decrypting the registration ciphertext. The relationship indicates that equality exists between the first and the second plaintext data sets.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: November 13, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Ryota Kamakari, Takeshi Shimoyama, Hiroshi Tsuda, Yoshinori Yaginuma, Avradip Mandal, Arnab Roy, Hart Montgomery, Toshiyuki Ishiguro, Kouhei Shigeta
  • Publication number: 20180262331
    Abstract: A key generation device includes a generation circuit, a concealment processing unit, and a cryptography processing unit. The generation circuit generates a value dependent on hardware. When acquiring a concealed cryptographic key, the concealment processing unit generates first data by performing a mask process to the concealed cryptographic key by using the value generated by the generation circuit, generates second data by decoding the first data by a first error correction decoding method, and generates a cryptographic key by decoding the second data by a second error correction decoding method. When acquiring the concealed cryptographic key and a plain text or an encrypted text, the cryptography processing unit acquires the cryptographic key corresponding to the concealed cryptographic key from the concealment processing unit, and encrypts the plain text or decrypts the encrypted text by using the cryptographic key.
    Type: Application
    Filed: March 5, 2018
    Publication date: September 13, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Yasuo NOGUCHI, Takeshi SHIMOYAMA
  • Patent number: 10020933
    Abstract: A memory stores therein first cryptographic information that represents an encrypted polynomial obtained by encrypting a first polynomial that corresponds to a first vector. From a terminal that receives second cryptographic information that represents an encrypted monomial obtained by encrypting a monomial generated by use of a random number, a receiver receives third cryptographic information that represents an encrypted result obtained by encrypting a result of a multiplication of a second polynomial that corresponds to a second vector by the monomial. A processor generates an encrypted polynomial that includes a result of an operation of the first vector and the second vector by use of the first cryptographic information, the third cryptographic information, and information that represents the monomial. An output interface outputs fourth cryptographic information that represents the encrypted polynomial generated by the generator.
    Type: Grant
    Filed: November 6, 2015
    Date of Patent: July 10, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Publication number: 20180174493
    Abstract: A mask is selected amongst a plurality of masks. A first masked random number is generated by converting a first random number using the selected mask, and a first key is generated from the first masked random number and a first biometric code generated from biometric information. In addition, mask information indicating the selected mask is stored. A second masked random number is generated by converting a second random number using the selected mask or a different mask having a predetermined relationship with the selected mask, and a second key is generated from the second masked random number and a second biometric code. A ciphertext is generated using one of the first key and the second key and an error-correction encoding method.
    Type: Application
    Filed: December 4, 2017
    Publication date: June 21, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Ryuichi Ohori, Takeshi SHIMOYAMA
  • Patent number: 9722782
    Abstract: An information processing method according to an embodiment causes a computer to execute a process of receiving an input of matching information encrypted with an encryption algorithm allowing a Hamming distance to be calculated with the matching information encrypted. The information processing method also causes the computer to execute a process of calculating a first Hamming distance between the received matching information and registered information that is different from encrypted registered information of a user, the registered information being encrypted with the encryption algorithm, using a processor. The information processing method also causes the computer to execute a process of determining legitimacy of the matching information based on whether the calculated first Hamming distance falls into a distance distribution representing matches with another person that is different from the user, using a processor.
    Type: Grant
    Filed: November 3, 2015
    Date of Patent: August 1, 2017
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Patent number: 9660991
    Abstract: A method includes receiving biometric data, the biometric data non-uniformly distributed and processing the biometric data to a level of randomness as a plaintext vector, the level of randomness associated with a security level. The method also includes encrypting the plaintext vector using a relational linearity encryption scheme to generate a linearity ciphertext representative of the plaintext vector, encrypting the plaintext vector using a relational proximity encryption scheme to generate a proximity ciphertext representative of the plaintext vector, and communicating the linearity ciphertext and the proximity ciphertext to an authentication server.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: May 23, 2017
    Assignee: FUJITSU LIMITED
    Inventors: Ryota Kamakari, Takeshi Shimoyama, Hiroshi Tsuda, Yoshinori Yaginuma, Avradip Mandal, Arnab Roy, Hart Montgomery, Toshiyuki Ishiguro, Kouhei Shigeta
  • Publication number: 20170085382
    Abstract: A method includes receiving biometric data, the biometric data non-uniformly distributed and processing the biometric data to a level of randomness as a plaintext vector, the level of randomness associated with a security level. The method also includes encrypting the plaintext vector using a relational linearity encryption scheme to generate a linearity ciphertext representative of the plaintext vector, encrypting the plaintext vector using a relational proximity encryption scheme to generate a proximity ciphertext representative of the plaintext vector, and communicating the linearity ciphertext and the proximity ciphertext to an authentication server.
    Type: Application
    Filed: February 10, 2016
    Publication date: March 23, 2017
    Applicant: FUJITSU LIMITED
    Inventors: Ryota KAMAKARI, Takeshi SHIMOYAMA, Hiroshi TSUDA, Yoshinori YAGINUMA, Avradip MANDAL, Arnab ROY, Hart MONTGOMERY, Toshiyuki ISHIGURO, Kouhei SHIGETA
  • Patent number: 9596083
    Abstract: A matching method includes: generating a first numerical vector; generating a second numerical vector by squaring each component of the first numerical vector and a third numerical vector by cubing each component of the first numerical vector; generating first to third polynomials by executing polynomial transformation of the first to third numerical vectors; encrypting the first to third polynomials by a homomorphic encryption scheme; executing a predetermined operation while keeping data used in the predetermined operation encrypted, by using fourth to sixth polynomials obtained by the polynomial transformation and the homomorphic encryption of fourth to sixth numerical vectors, wherein the fourth numerical vector is generated by numerically vectorizing second text, the fifth numerical vector is generated by squaring each component of the fourth numerical vector, and the sixth numerical vector is generated by cubing each component of the fourth numerical vector; and decrypting a result of the predetermined
    Type: Grant
    Filed: April 27, 2015
    Date of Patent: March 14, 2017
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Publication number: 20170019255
    Abstract: A method of equality verification using relational encryption including receiving a relational key that includes a first relational key component and a registration ciphertext that includes an encryption of a first plaintext data set. The method includes storing the registration ciphertext without decrypting the registration ciphertext. After the storing of the registration ciphertext, the method includes receiving an authentication request and communicating a safeguard data set that includes a random challenge in response to the authentication request. The method includes receiving an encrypted response that is generated based on the safeguard data set and a second plaintext data set. The method includes verifying a relationship between the encrypted response and the registration ciphertext using the relational key without decrypting the encrypted response and without decrypting the registration ciphertext. The relationship indicates that equality exists between the first and the second plaintext data sets.
    Type: Application
    Filed: February 10, 2016
    Publication date: January 19, 2017
    Applicant: FUJITSU LIMITED
    Inventors: Ryota KAMAKARI, Takeshi SHIMOYAMA, Hiroshi TSUDA, Yoshinori YAGINUMA, Avradip MANDAL, Arnab ROY, Hart MONTGOMERY, Toshiyuki ISHIGURO, Kouhei SHIGETA
  • Patent number: 9531539
    Abstract: A non-transitory computer-readable recording medium stores an information processing program that causes a computer to execute a process including, generating feature information based on organism information of a user; calculating a first cryptogram based on a logical operation of the feature information generated and a random number; and encrypting the first cryptogram into a second cryptogram by using a cryptographic algorithm capable of calculating a Hamming distance in an encrypted state.
    Type: Grant
    Filed: December 19, 2014
    Date of Patent: December 27, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Takeshi Shimoyama, Masaya Yasuda, Jun Kogure
  • Patent number: 9509493
    Abstract: An encrypted first polynomial that is obtained by encrypting, in a homomorphic encryption method that handles a polynomial processing, a first polynomial, is received from another computer. The first polynomial is represented by using, as coefficients, components of a first binary vector generated from first data in first order that is either ascending order or descending order with respect to degree of the first polynomial. Then, a predetermined processing in an encrypted text space is performed by using the encrypted first polynomial and an encrypted second polynomial that is obtained by encrypting a second polynomial in the homomorphic encryption method. The second polynomial is represented by using, as coefficients, components of a second binary vector generated from second data in second order that is different from the first order with respect to degree of the second polynomial. Then, a result of the predetermined processing is sent back.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: November 29, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Patent number: 9473302
    Abstract: A ciphertext processing device acquires a first polynomial into which first text data is converted with a first order and which is encrypted with a first public key and a first square-value polynomial into which square-value vector data of each component of the first text data is converted with the first order and which is encrypted with the first public key. The ciphertext processing device acquires a second polynomial into which second text data is converted with a second order and which is encrypted with the first public key and a second square-value polynomial into which square-value vector data of each component of the second text data is converted with the second order and which is encrypted with the first public key. The ciphertext processing device determines whether the second text data is included in the first text data, using the each polynomial.
    Type: Grant
    Filed: March 2, 2015
    Date of Patent: October 18, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Patent number: 9438423
    Abstract: An encryption server receives encrypted data which is encrypted by using a public key of a first user and which is added with auxiliary information calculated using a combination of a secret key and the public key of the first user and data to be encrypted. Then, the encryption server generates re-encrypted data obtained by re-encrypting the encrypted data using the auxiliary information added to the encrypted data, a public key of a second user, and encrypted information related to the secret key of the first user which is encrypted with the public key of the second user.
    Type: Grant
    Filed: February 27, 2015
    Date of Patent: September 6, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Publication number: 20160182226
    Abstract: An information processing method according to an embodiment causes a computer to execute a process of receiving an input of matching information encrypted with an encryption algorithm allowing a Hamming distance to be calculated with the matching information encrypted. The information processing method also causes the computer to execute a process of calculating a first Hamming distance between the received matching information and registered information that is different from encrypted registered information of a user, the registered information being encrypted with the encryption algorithm, using a processor. The information processing method also causes the computer to execute a process of determining legitimacy of the matching information based on whether the calculated first Hamming distance falls into a distance distribution representing matches with another person that is different from the user, using a processor.
    Type: Application
    Filed: November 3, 2015
    Publication date: June 23, 2016
    Applicant: FUJITSU LIMITED
    Inventors: MASAYA YASUDA, Takeshi Shimoyama, Jun KOGURE
  • Publication number: 20160173275
    Abstract: A memory stores therein first cryptographic information that represents an encrypted polynomial obtained by encrypting a first polynomial that corresponds to a first vector. From a terminal that receives second cryptographic information that represents an encrypted monomial obtained by encrypting a monomial generated by use of a random number, a receiver receives third cryptographic information that represents an encrypted result obtained by encrypting a result of a multiplication of a second polynomial that corresponds to a second vector by the monomial. A processor generates an encrypted polynomial that includes a result of an operation of the first vector and the second vector by use of the first cryptographic information, the third cryptographic information, and information that represents the monomial. An output interface outputs fourth cryptographic information that represents the encrypted polynomial generated by the generator.
    Type: Application
    Filed: November 6, 2015
    Publication date: June 16, 2016
    Applicant: FUJITSU LIMITED
    Inventors: MASAYA YASUDA, Takeshi Shimoyama, Jun KOGURE
  • Publication number: 20150318991
    Abstract: A matching method includes: generating a first numerical vector; generating a second numerical vector by squaring each component of the first numerical vector and a third numerical vector by cubing each component of the first numerical vector; generating first to third polynomials by executing polynomial transformation of the first to third numerical vectors; encrypting the first to third polynomials by a homomorphic encryption scheme; executing a predetermined operation while keeping data used in the predetermined operation encrypted, by using fourth to sixth polynomials obtained by the polynomial transformation and the homomorphic encryption of fourth to sixth numerical vectors, wherein the fourth numerical vector is generated by numerically vectorizing second text, the fifth numerical vector is generated by squaring each component of the fourth numerical vector, and the sixth numerical vector is generated by cubing each component of the fourth numerical vector; and decrypting a result of the predetermined
    Type: Application
    Filed: April 27, 2015
    Publication date: November 5, 2015
    Inventors: MASAYA YASUDA, Takeshi Shimoyama, Jun KOGURE
  • Patent number: 9166785
    Abstract: A device that uses homomorphic encryption is disclosed. The device includes a public key data generator configured to generate public key data, and a secret key data generator configured to generate secret key data that includes, as a secret key, an integer that is an element of a matrix obtained as a product of the first public key matrix element and an inverse matrix of the secret key matrix and that is not a multiple of the plain text space size.
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: October 20, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure
  • Publication number: 20150280914
    Abstract: A ciphertext processing device acquires a first polynomial into which first text data is converted with a first order and which is encrypted with a first public key and a first square-value polynomial into which square-value vector data of each component of the first text data is converted with the first order and which is encrypted with the first public key. The ciphertext processing device acquires a second polynomial into which second text data is converted with a second order and which is encrypted with the first public key and a second square-value polynomial into which square-value vector data of each component of the second text data is converted with the second order and which is encrypted with the first public key. The ciphertext processing device determines whether the second text data is included in the first text data, using the each polynomial.
    Type: Application
    Filed: March 2, 2015
    Publication date: October 1, 2015
    Inventors: Masaya YASUDA, Takeshi SHIMOYAMA, Jun KOGURE
  • Publication number: 20150270964
    Abstract: An encryption server receives encrypted data which is encrypted by using a public key of a first user and which is added with auxiliary information calculated using a combination of a secret key and the public key of the first user and data to be encrypted. Then, the encryption server generates re-encrypted data obtained by re-encrypting the encrypted data using the auxiliary information added to the encrypted data, a public key of a second user, and encrypted information related to the secret key of the first user which is encrypted with the public key of the second user.
    Type: Application
    Filed: February 27, 2015
    Publication date: September 24, 2015
    Inventors: Masaya YASUDA, Takeshi SHIMOYAMA, Jun KOGURE
  • Patent number: 9100185
    Abstract: A device that uses homomorphic encryption is disclosed. The device obtains a first encrypted polynomial, a second encrypted polynomial, a first encrypted weight, and a second encrypted weight by respectively encrypting a first polynomial, a second polynomial, a first weight, and a second weight by using a homomorphic encryption scheme, and obtains an encrypted secure distance corresponding to encryption of a secure distance.
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: August 4, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Masaya Yasuda, Takeshi Shimoyama, Jun Kogure