Patents by Inventor Hiroto TAMIYA

Hiroto TAMIYA 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: 20250240173
    Abstract: An certificate issuer generates auxiliary data using a signing key and first biometric information, generates a certificate including a verification key corresponding to the signing key, and transmits the certificate and the auxiliary data to a certificate holder, which obtains the second biometric, receives the certificate and the auxiliary data transmitted from the certificate issuer, generates, using the second biometric information and the auxiliary data, a signature, and transmit a certificate presentation and the signature to a certificate verifier, which receives the certificate presentation and the signature from the certificate holder and verifies the signature using the verification key include d in the certificate.
    Type: Application
    Filed: January 7, 2025
    Publication date: July 24, 2025
    Applicant: NEC Corporation
    Inventors: Hiroto TAMIYA, Saki OTSUKI, Yoshitomo WARASHINA, Toshiyuki ISSHIKI
  • Publication number: 20250193021
    Abstract: A first signature generation apparatus receives and registers first auxiliary data generated based on a first signature key and first biometric information and a second signature generation apparatus acquires second biometric information, generates a second distributed key, generates second auxiliary data using the second biometric information and the second distributed key and transmits a message and the second auxiliary data to the first signature generation apparatus, which generates a first distributed key using the first auxiliary data and the second auxiliary data, wherein the first and second signature generation apparatuses execute a distributed signing process using at least the first and second distributed keys to generate a signature for the message.
    Type: Application
    Filed: November 22, 2024
    Publication date: June 12, 2025
    Applicant: NEC Corporation
    Inventors: Hiroto TAMIYA, Saki OTSUKI, Haruna FUKUDA, Toshiyuki ISSHIKI
  • Patent number: 12278909
    Abstract: A signature verification system includes: a signature apparatus configured to sign a first chameleon hash value, an unmodifiable part of the data, and a second chameleon hash value of an entirety of the data; a changing apparatus configured to change a public key for the changers of the temporary delegator to a public key for changers of an actual delegator, using a private key for the changers; a delegator changing apparatus configured to change a modifiable part of the data, using a private key for the changers of the actual delegator; and a verifying apparatus configured to verify the signature using the public key for the changers and the public key for the changers of the actual delegator.
    Type: Grant
    Filed: June 2, 2020
    Date of Patent: April 15, 2025
    Assignee: NEC Corporation
    Inventors: Hiroto Tamiya, Batnyam Enkhtaivan, Toshiyuki Isshiki
  • Patent number: 12242644
    Abstract: A collation system 10 includes divide registered information to first information and second information, and to provide the second information to a server apparatus 200, perform a first step for similarity calculation between the registered information and collation information inputted for collation with the registered information, based on the collation information and the first information, send a calculation result of the first step to the server apparatus 200, perform a second step for the similarity calculation based on the calculation result of the first step received from a client terminal 100, and the second information, send a calculation result of the second step to the client terminal 100, and perform a third step for the similarity calculation based on the calculation result of the second step received from the server apparatus 200, and the first information to calculate similarity between the registered information and the collation information.
    Type: Grant
    Filed: May 29, 2020
    Date of Patent: March 4, 2025
    Assignee: NEC CORPORATION
    Inventors: Toshiyuki Isshiki, Hiroto Tamiya, Masahiro Nara, Toshihiko Okamura
  • Publication number: 20250053638
    Abstract: A matching system that uses a matching apparatus to match registered information input to a first transformation apparatus and matching information input to a second transformation apparatus, wherein the first transformation apparatus generates a registered feature vector from the registered information, generates a registered concealed vector through calculating a product of the registered feature vector and the registration key matrix by using a regular matrix selected at random as a registration key matrix, and transmits the registered concealed vector to the matching apparatus, the second transformation apparatus generates a matching feature vector from the matching information, generates a matching concealed vector through calculating a product of the matching feature vector and an inverse matrix of the registration key matrix, and transmits the matching concealed vector to the matching apparatus, the matching apparatus calculates an inner product of the registered concealed vector and the matching conce
    Type: Application
    Filed: December 27, 2021
    Publication date: February 13, 2025
    Applicant: NEC Corporation
    Inventors: Haruna FUKUDA, Toshiyuki ISSHIKI, Kengo MORI, Hiroto TAMIYA
  • Patent number: 12200147
    Abstract: The client includes a random number generation unit which generates a random number, a concealed information storage unit which stores concealed information generated by concealing registered information and the generated random number using a secret key, and a response computation unit which, on the basis of a challenge transmitted from the server, the collation information input for collation with the registered information, and the concealed information, computes a response corresponding to the challenge and including a concealed index, generated by concealing an index indicating closeness between the registered information and the collation information. The server includes a challenge generation unit which generates the challenge using a public key corresponding to the secret key, and a determination unit which uses the public key and the random number transmitted from the client to determine whether or not the response transmitted from the client corresponds to the challenge.
    Type: Grant
    Filed: June 5, 2019
    Date of Patent: January 14, 2025
    Assignee: NEC CORPORATION
    Inventors: Toshiyuki Isshiki, Toshihiko Okamura, Haruna Fukuda, Hiroto Tamiya, Masahiro Nara
  • Patent number: 12199638
    Abstract: In order to provide an information concealing apparatus, an information reconfiguring apparatus, an information concealing system, an information concealing method, an information reconfiguring method, an information concealing program, and an information reconfiguring program to reduce information leakage risks, an information concealing system includes an information concealing apparatus, and an information reconfiguring apparatus. The information concealing apparatus generates a codeword capable of error-correcting concealment-side input information, generates noise including a predetermined error, and generates concealment information capable to reconfigure the concealment-side input information, by adding the concealment-side input information and the noise to the codeword. The information reconfiguring apparatus reconfigures the codeword from the concealment information, based on reconfiguration-side input information and the concealment information.
    Type: Grant
    Filed: November 17, 2020
    Date of Patent: January 14, 2025
    Assignee: NEC CORPORATION
    Inventors: Hiroto Tamiya, Toshiyuki Isshiki
  • Patent number: 12155769
    Abstract: In order to provide an information matching system achieving an information matching scheme that takes a lower cost and uses secure biometric information, the information matching system includes a concealment apparatus, a decryption apparatus, and a similarity calculating apparatus. The concealment apparatus transmits, to the similarity calculating apparatus, concealed information including information concealing obtained matching information by linear conversion using random numbers. The similarity calculating apparatus calculates, from obtained one or more pieces of registration information and the concealed information received from the concealment apparatus, a concealed similarity which is a value concealing a similarity between the matching information and the registration information, and to transmit the calculated concealed similarity to the decryption apparatus.
    Type: Grant
    Filed: October 4, 2019
    Date of Patent: November 26, 2024
    Assignee: NEC CORPORATION
    Inventors: Haruna Fukuda, Hiroto Tamiya, Toshihiko Okamura, Toshiyuki Isshiki, Masahiro Nara
  • Patent number: 12143482
    Abstract: A storing information generation apparatus obtains registration information and an identifier capable of identifying the registration information, to generate a first individual key from the common key and the identifier, and to generate storing information obtained by linearly converting the registration information using the common key and the first individual key. A matching information concealment apparatus obtains matching information to generate concealed matching information concealing the matching information using an encryption key. A concealed similarity calculation apparatus calculates a concealed similarity from the storing information and the concealed matching information. A decryption apparatus generates a second individual key from the common key and the identifier, and calculates a similarity between the registration information and the matching information from the concealed similarity, a decryption key corresponding to the encryption key, the common key, and the second individual key.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: November 12, 2024
    Assignee: NEC Corporation
    Inventors: Haruna Fukuda, Toshiyuki Isshiki, Masahiro Nara, Hiroto Tamiya, Toshihiko Okamura
  • Publication number: 20240356725
    Abstract: An authentication system transmits a ciphertext of authentication information from an authenticatee apparatus to an authenticator apparatus using homomorphic encryption with a public key encryption scheme, the authenticator apparatus issues a first random number to the authenticatee apparatus, the authenticatee apparatus generates a second random number and transmits to the authenticator apparatus a first element generated with a public key using the first and the second random numbers and a second element generated with a public key using the second random number, and the authenticator apparatus modifies the second element using the first random number to obtain a ciphertext of the authentication information.
    Type: Application
    Filed: August 31, 2021
    Publication date: October 24, 2024
    Applicant: NEC Corporation
    Inventors: Hiroto TAMIYA, Toshiyuki ISSHIKI, Kengo MORI, Haruna FUKUDA, Masahiro NARA
  • Patent number: 12120229
    Abstract: Provided is an encryption system that suppresses a communication cost from a key issuing system to a user and controls input to a function in the unit of data. The encryption system includes an encrypting apparatus, a signature apparatus, and a security execution apparatus. The encrypting apparatus generates pseudo-random numbers different for respective pieces of data, and encrypts the generated pseudo-random numbers together with the pieces of data. The signature apparatus regenerates the pseudo-random numbers used by the encrypting apparatus for encrypting the respective pieces of data, and generates control information for certifying validity of the pieces of the data from the regenerated pseudo-random numbers.
    Type: Grant
    Filed: July 17, 2019
    Date of Patent: October 15, 2024
    Assignee: NEC CORPORATION
    Inventors: Hiroto Tamiya, Toshiyuki Isshiki, Batnyam Enkhtaivan
  • Publication number: 20240291646
    Abstract: In order to realize encryption processing capable of suppressing the degradation of collation accuracy and reducing the risk of information leakage, a terminal apparatus for encrypting input information to be input for collation is provided, the terminal apparatus being configured to perform transformation parameter generation processing for generating a transformation parameter based on a first parameter stored in a storage area and a second parameter that is different from the first parameter, and encrypt the input information input for collation using the transformation parameter to generate encrypted input information.
    Type: Application
    Filed: June 25, 2021
    Publication date: August 29, 2024
    Applicant: NEC Corporation
    Inventors: Kengo MORI, Toshiyuki Isshiki, Sanami Nakagawa, Hiroto Tamiya, Masahiro Nara
  • Publication number: 20240273173
    Abstract: Provided is a registration information generation apparatus for generating registration information based on registration-side input information including one or both of elements corresponding to a first set and elements corresponding to a second set, the registration information generation apparatus being configured to generate intermediate information by performing distribution processing for performing secret-sharing for the elements corresponding to the first set in input information, and a duplication processing for duplicating the elements corresponding to the second set in input information, and generate the registration information by replacing a sort order of elements in the intermediate information using a replacement key.
    Type: Application
    Filed: May 26, 2021
    Publication date: August 15, 2024
    Applicant: NEC Corporation
    Inventors: Toshiyuki ISSHIKI, Hiroto TAMIYA
  • Patent number: 12063293
    Abstract: A collation system 20, which is provided with a client 30 and a server 40, the client 30 includes: a random number generation unit 31 which generates a random number; a concealed information storage unit 32 which stores concealed information generated by concealing registered information and the generated random number using a concealment key; and a concealed index computation unit 33 which, on the basis of the collation information input for collation with the registered information and the concealed information, computes a concealed index, generated by concealing an index indicating closeness between the registered information and the collation information; the server 40 includes a determination unit 41 which uses a release key corresponding to the concealment key and the random number transmitted from the client 30 to determine whether or not the index can be acquired from the concealed index transmitted from the client 30.
    Type: Grant
    Filed: December 12, 2018
    Date of Patent: August 13, 2024
    Assignee: NEC CORPORATION
    Inventors: Toshiyuki Isshiki, Haruna Fukuda, Hiroto Tamiya, Masahiro Nara
  • Publication number: 20240214178
    Abstract: A homomorphic cyclic operation system performs a homomorphic cyclic operation on a periodic array of data using homomorphic encryption having a homomorphic operation defined with respect to at least one multiplication and comprises: an encryption apparatus that encrypts the periodic array of data by storing it in the coefficients of an indeterminate polynomial to generate a ciphertext of periodic data; and a homomorphic cyclic operation apparatus that shifts the periodic array of data in the ciphertext of the periodic data by applying the indeterminate raised to the power of a shift amount to the ciphertext of the periodic data.
    Type: Application
    Filed: July 29, 2021
    Publication date: June 27, 2024
    Applicant: NEC Corporation
    Inventors: Hiroto TAMIYA, Toshiyuki ISSHIKI, Kengo MORI, Sanami NAKAGAWA
  • Publication number: 20240171373
    Abstract: A similarity calculation system calculating the similarity between a first vector and a second vector using homomorphic encryption having homomorphic operations defined with respect to at least one multiplication and a plurality of additions obtains the similarity between the first and the second vectors by using the homomorphic operations to calculate the inner product of the first encrypted vector obtained by using a public key for the homomorphic encryption to encrypt a row corresponding to the value of a component of the first vector extracted from a weighted similarity table of the similarity between each component of the first and the second vectors and the second encrypted vector obtained by transforming the value of a component of the second vector into a component in a unit vector that becomes 1 and encrypting the transformed result with the public key for the homomorphic encryption.
    Type: Application
    Filed: March 23, 2021
    Publication date: May 23, 2024
    Applicant: NEC Corporation
    Inventors: Hiroto TAMIYA, Toshiyuki ISSHIKI, Kengo MORI, Sanami NAKAGAWA
  • Publication number: 20240121075
    Abstract: A similarity calculation system calculating a distance between a first vector stored in a similarity calculation apparatus and a second vector entered from an input terminal wherein the similarity calculation apparatus transmits to the input terminal a ciphertext of each element of the first vector and a weighted distance table with respect to combinations of possible values of the elements of the first vector and the second vector, and the input terminal refers to the weighted distance table to calculate a ciphertext of element distances for all combinations of the value of a single element of the second vector and possible values of elements of the first vector, calculates the ciphertexts of the sum of the element distances for each element of the second vector using additive homomorphic encryption, and transmits the ciphertext of the sum to the similarity calculation apparatus.
    Type: Application
    Filed: February 10, 2021
    Publication date: April 11, 2024
    Applicant: NEC Corporation
    Inventors: Sanami NAKAGAWA, Toshiyuki ISSHIKI, Hiroto TAMIYA
  • Publication number: 20240104182
    Abstract: A conventional biometric authentication system has been time-consuming and labor-intensive for users since the users are requested to re-register their biometric information. According to an aspect of the present disclosure, a biometric authentication system includes an update value generation unit configured to generate an update value, a first update processing unit configured to update, using the update value, a template generated based on biometric information, and a second update processing unit configured to update, using the update value, a verification key generated along with the template based on the biometric information using the update value.
    Type: Application
    Filed: January 29, 2021
    Publication date: March 28, 2024
    Applicant: NEC Corporation
    Inventors: Masahiro NARA, Toshihiko OKAMURA, Toshiyuki ISSHIKI, Kengo MORI, Hiroto TAMIYA
  • Publication number: 20240039718
    Abstract: In a recovery verification system, a template storage unit stores a template acquired by encrypting registration input information being biometric information about a registrant by using a secret key. A random number generation unit generates a random number in response to a request from the client. A protected template generation unit conceals the template by the random number, and transmits a protected template to the client. A determination unit acquires, from the client, information about a concealment index that is acquired by concealing a degree of similarity between registration input information and collation information being biometric information about an authenticated subject and is calculated based on the collation information and the protected template. A determination unit generates an index acquired by decrypting the concealment index by using a public key associated with the secret key and the random number, and performs authentication, based on the index.
    Type: Application
    Filed: December 16, 2020
    Publication date: February 1, 2024
    Applicant: NEC Corporation
    Inventors: Masahiro NARA, Toshihiko OKAMURA, Toshiyuki ISSHIKI, Hiroto TAMIYA
  • Publication number: 20230412362
    Abstract: An information concealing system includes: an information concealing apparatus configured to generate a pseudo-random number, convert first information into first conversion information by using the pseudo-random number, and cause a concealment information generating unit to generate first concealment information capable to reconfigure the first information, based on the first conversion information; and an information reconfiguring apparatus configured to extract information related to a seed from the first concealment information, generate a reconfiguration-side pseudo-random number, based on the information related to the seed, convert input second information into second conversion information by using the reconfiguration-side pseudo-random number, and reconfigure the first information concealed as the first concealment information, based on the second conversion information and the first concealment information.
    Type: Application
    Filed: November 17, 2020
    Publication date: December 21, 2023
    Applicant: NEC Corporation
    Inventors: Hiroto TAMIYA, Toshiyuki Isshiki