Patents by Inventor Koutarou Suzuki
Koutarou Suzuki 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).
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Patent number: 11902428Abstract: A key exchange system in which a shared key is generated for executing encrypted communication between communication apparatuses according to an authenticated key exchange protocol using ID-based encryption, wherein each communication apparatus includes a memory and a processor configured to generate a short-term private key by using a private key of the communication apparatus; generate a short-term public key of the communication apparatus by using the short-term private key; generate private information on the communication apparatus by using the short-term private key, a short-term public key generated by another communication apparatus, and public information generated by the communication apparatus and said another communication apparatus or public information generated by a key delivering center; and generate the shared key for executing encrypted communication with said another communication apparatus by executing a pairing operation using the private key of the communication apparatus and the privateType: GrantFiled: July 16, 2020Date of Patent: February 13, 2024Assignees: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NATIONAL UNIVERSITY CORPORATION TOYOHASHI UNIVERSITY OF TECHNOLOGYInventors: Junichi Tomida, Fumitaka Hoshino, Akira Nagai, Atsushi Fujioka, Koutarou Suzuki
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Publication number: 20220303124Abstract: A key exchange system in which a shared key is generated for executing encrypted communication between communication apparatuses according to an authenticated key exchange protocol using ID-based encryption, wherein each communication apparatus includes a memory and a processor configured to generate a short-term private key by using a private key of the communication apparatus; generate a short-term public key of the communication apparatus by using the short-term private key; generate private information on the communication apparatus by using the short-term private key, a short-term public key generated by another communication apparatus, and public information generated by the communication apparatus and said another communication apparatus or public information generated by a key delivering center; and generate the shared key for executing encrypted communication with said another communication apparatus by executing a pairing operation using the private key of the communication apparatus and the privateType: ApplicationFiled: July 16, 2020Publication date: September 22, 2022Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NATIONAL UNIVERSITY CORPORATION TOYOHASHI UNIVERSITY OF TECHNOLOGYInventors: Junichi TOMIDA, Fumitaka HOSHINO, Akira NAGAI, Atsushi FUJIOKA, Koutarou SUZUKI
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Patent number: 11424913Abstract: A key exchange system method safely conceal secret information recorded on a blockchain. A first terminal includes a license issuing unit that generates a first transaction including a first public key, a first key storage region that retains a first secret key, and a first encrypting and decrypting unit that generates a common key using deal-specific information, a second public key, and the first secret key, and a second terminal includes a license requesting unit that generates a second transaction including the second public key, a second key storage region that retains a second secret key, and a second encrypting and decrypting unit that generates the common key using deal-specific information, the first public key, and the second secret key. The first encrypting and decrypting unit encrypts secret information using the common key. The second encrypting and decrypting unit decrypts the encrypted secret information using the common key.Type: GrantFiled: June 20, 2018Date of Patent: August 23, 2022Assignee: Nippon Telegraph and Telephone CorporationInventors: Hiroki Watanabe, Tsunekazu Saito, Koutarou Suzuki, Shigenori Ohashi, Shigeru Fujimura, Atsushi Nakadaira
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Patent number: 11095429Abstract: At least any one of input keys KA0, KA1, KB?0, and KB?1 is set so that the input keys KA0, KA1, KB?0, and KB?1 which satisfy KA1?KA0=KB?1?KB?0=di are obtained, and an output key Kig(I(A), I(B)) corresponding to an output value gi(I(A), I(B)) is set by using the input keys KA0, KA1, KB?0, and KB?1, where input values of a gate that performs a logical operation are I(A), I(B)?{0, 1}, an output value of the gate is gi(I(A), I(B))?{0, 1}, an input key corresponding to the input value I(A) is KAI(A), and an input key corresponding to the input value I(B) is KB?I(B).Type: GrantFiled: November 9, 2017Date of Patent: August 17, 2021Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Koutarou Suzuki, Ryo Kikuchi, Carmen Kempka
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Patent number: 10804760Abstract: A rotor includes: a cylindrical rotor core fixed to an outer peripheral side of a rotary shaft rotatable about an axis center, the rotor core including multiple first slots arranged at intervals in the peripheral direction of the rotor core and penetrating the rotor core in the axis direction of the rotary shaft, and multiple second slots formed at an inner position of the rotor core with respect to the first slots, arranged at intervals in the peripheral direction of the rotor core, and penetrating the rotor core in the axis direction of the rotary shaft; and a secondary conductor including multiple conductor bars arranged in the first slots and the second slots, and a pair of ring-like end rings arranged at opposite end surfaces of the rotor core and connecting end portions of the multiple conductor bars.Type: GrantFiled: June 15, 2018Date of Patent: October 13, 2020Assignee: FANUC CORPORATIONInventor: Koutarou Suzuki
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Publication number: 20200228310Abstract: At least any one of input keys KA0, KA1, KB?0, and KB?1 is set so that the input keys KA0, KA1, KB?0, and KB?1 which satisfy KA1?KA0=KB?1?KB?0=di are obtained, and an output key Kig(I(A), I(B)) corresponding to an output value gi(I(A), I(B)) is set by using the input keys KA0, KA1, KB?0, and KB?1, where input values of a gate that performs a logical operation are I(A), I(B)?{0, 1}, an output value of the gate is gi(I(A), I(B))?{0, 1}, an input key corresponding to the input value I(A) is KAI(A), and an input key corresponding to the input value I(B) is KB?I(B).Type: ApplicationFiled: November 9, 2017Publication date: July 16, 2020Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Koutarou SUZUKI, Ryo KIKUCHI, Carmen KEMPKA
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Publication number: 20200127818Abstract: A key exchange system method safely conceal secret information recorded on a blockchain. A first terminal includes a license issuing unit that generates a first transaction including a first public key, a first key storage region that retains a first secret key, and a first encrypting and decrypting unit that generates a common key using deal-specific information, a second public key, and the first secret key, and a second terminal includes a license requesting unit that generates a second transaction including the second public key, a second key storage region that retains a second secret key, and a second encrypting and decrypting unit that generates the common key using deal-specific information, the first public key, and the second secret key. The first encrypting and decrypting unit encrypts secret information using the common key. The second encrypting and decrypting unit decrypts the encrypted secret information using the common key.Type: ApplicationFiled: June 20, 2018Publication date: April 23, 2020Inventors: Hiroki Watanabe, Tsunekazu Saito, Koutarou Suzuki, Shigenori Ohashi, Shigeru Fujimura, Atsushi Nakadaira
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Publication number: 20200071443Abstract: A graft copolymer (C) having a main chain portion of a precursor polymer (A) and a graft portion from a polymer (B), wherein a core portion of the solid product comprises the main chain portion derived from (A), a shell portion comprises the graft portion derived from (B), and the solid product satisfies: Infrared absorption spectroscopic measurement of a section passing through a center (x) of the solid product, a point (z) on a surface where a distance between the center (x) and the surface is shortest, and a middle point (y) of a line connecting the center (x) and the point (z), absorbance (Abs) satisfies X<0.01, Y<0.01, and Z?0.01, wherein X, Y, and Z represent values of Abs (key band of the polymer (B))/Abs (key band of the polymer (A)) at the center (x), the middle point (y) and the point (z).Type: ApplicationFiled: December 7, 2017Publication date: March 5, 2020Applicant: MITSUI CHEMICALS, INC.Inventors: Akihide MORI, Masahiko OKAMOTO, Katsuyoshi HARADA, Takahiro YAMADA, Shuhei YAMAMOTO, Kiyoshi TAKAHASHI, Kiyoshi YAMAMURA, Koutarou SUZUKI, Ryouichi SEKI, Shinya MATSUNAGA
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Publication number: 20190013709Abstract: A rotor includes: a cylindrical rotor core fixed to an outer peripheral side of a rotary shaft rotatable about an axis center, the rotor core including multiple first slots arranged at intervals in the peripheral direction of the rotor core and penetrating the rotor core in the axis direction of the rotary shaft, and multiple second slots formed at an inner position of the rotor core with respect to the first slots, arranged at intervals in the peripheral direction of the rotor core, and penetrating the rotor core in the axis direction of the rotary shaft; and a secondary conductor including multiple conductor bars arranged in the first slots and the second slots, and a pair of ring-like end rings arranged at opposite end surfaces of the rotor core and connecting end portions of the multiple conductor bars.Type: ApplicationFiled: June 15, 2018Publication date: January 10, 2019Applicant: FANUC CORPORATIONInventor: Koutarou SUZUKI
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Publication number: 20160241113Abstract: A rotor is formed with a flow path for supplying a cooling fluid. The flow path has a supply path extending inside the rotor, a plurality of branch paths branching off from the supply path, and return paths extending from the respective branch paths toward a base end side of the supply path. The branch paths are at positions distant from each other in a direction parallel to a rotational axis of the rotor.Type: ApplicationFiled: February 9, 2016Publication date: August 18, 2016Inventor: Koutarou Suzuki
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Patent number: 8964988Abstract: A sharing apparatus independently shares a value corresponding to each element ?(?, i, ?)·g2 of basis vectors bi*(?) among each subset SUB(?) consisting of H(?) share management apparatuses PA(?, 1), . . . , PA(?, H(?)) to generate share information SH(?, i, ?, ?, h(?)) corresponding to each element ?(?, i, ?)·g2. The share management apparatus PA(?, h(?)) generates a share secret value DSH(?, ?, h(?)) by performing a common calculation common in the subset SUB(?) on common information shared in the subset SUB(?) and the share information SH(?, i, ?, ?, h(?)). An acquisition apparatus generates reconstructed secret values SUBSK(?, ?) for each subset SUB(?) by performing a reconstruction processing for the subset SUB(?) and generates generation information D*(?) from the reconstructed secret values SUBSK(?, ?).Type: GrantFiled: July 22, 2011Date of Patent: February 24, 2015Assignee: Nippon Telegraph and Telephone CorporationInventors: Ryo Nishimaki, Koutarou Suzuki
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Patent number: 8938068Abstract: An information output apparatus identifies, according to a rule established for each of functional encryption protocols or a rule established for each combination of the protocols, one or more identifiers corresponding to a particular functional encryption protocol or a combination of the particular protocols, sets a particular piece of first correspondence information corresponding to the identifier or identifiers, and outputs first information which is a ciphertext or key information of the functional encryption scheme that corresponds to the particular piece of first correspondence information.Type: GrantFiled: July 30, 2010Date of Patent: January 20, 2015Assignee: Nippon Telegraph and Telephone CorporationInventors: Tetsutaro Kobayashi, Koutarou Suzuki
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Publication number: 20150015098Abstract: In a rotor of a motor according to the present invention, a plurality of flow passages spaced apart from each other around an axis of rotation, each of which extends so as to be slanted relative to an axis of rotation and open to an exterior space of the rotor at both ends of the rotor. The flow passages are configured so that adjacent flow passages are slanted alternately in opposite directions and that a fluid for cooling the rotor circulates through the flow passages.Type: ApplicationFiled: July 10, 2014Publication date: January 15, 2015Inventor: Koutarou Suzuki
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Patent number: 8619980Abstract: Hierarchical cryptography expressed in a general semiordered structure other than a tree structure is implemented. In information generation, random numbers ?v and (?vj)j?w(v)?Zq are generated; main information kv=?v?i?{1, . . . , N-1}\w(v)vibi*+bN* is calculated; and derivation information kvj=?vj?i?{1, . . . , N-1}\w(v)vibi*+bj* is calculated for each j?w(v). In information derivation, random numbers ?u and (?uj)j?w(u)?Zq are generated; main information ku=?u?i?w(v)\w(u)uikvi+kv is calculated; and derivation information kuj=?uj?i?w(v)\w(u)uikvi+kvj is calculated for each j?w(v).Type: GrantFiled: April 23, 2010Date of Patent: December 31, 2013Assignee: Nippon Telegraph and Telephone CorporationInventors: Koutarou Suzuki, Ryo Nishimaki
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Patent number: 8549290Abstract: A secure secret sharing system is implemented. Shares SH(?, h(?)) are generated by secret sharing of secret information separately for each subset SUB(?); each of share management apparatuses PA(?, h(?)) generates a shared secret value DSH(?, h(?)) by performing a common operation to a corresponding share SH(?, h(?)) and common information containing a common value ?(?) shared in each subset SUB(?); and an acquisition apparatus generates a reconstructed secret value SUBSK(?) by reconstruction processing for each subset SUB(?), using a plurality of shared secret values DSH(?, h(?)) corresponding to the same subset SUB(?), and generates generation information SK by using the reconstructed secret values SUBSK(?).Type: GrantFiled: April 23, 2010Date of Patent: October 1, 2013Assignee: Nippon Telegraph and Telephone CorporationInventors: Ryo Nishimaki, Koutarou Suzuki
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Patent number: 8515060Abstract: Security against CCA is improved without providing space for just improving the security against CCA in a ciphertext space. In encryption processing, a first ciphertext C1 is calculated from a plaintext M and a symmetric key K; a value containing a value corresponding to the symmetric key K and a value corresponding to the first ciphertext C1 is put into a collision-resistant function H to calculate a function value of the function H; and r corresponding to the function value is used to calculate second ciphertext C2=r·(??=1nv?·b?)+?·bn+1?G1n+1. In decryption processing, the second ciphertext C2?G1n+1 and key information D1*=?·(??=1nw?·b?*)+bn+1*?G2n+1 are put into a bilinear function e to calculate a function value S˜=e(C2, D1*)?GT; a value corresponding to the function value S˜ and the first ciphertext C1 are put into the collision-resistant function H to calculate a function value of the function H; and it is judged whether r˜ corresponding to the function value satisfies C2=r˜·(??=1nv?·b?)+?˜·bn+1?G1n+1.Type: GrantFiled: April 23, 2010Date of Patent: August 20, 2013Assignee: Nippon Telegraph and Telephone CorporationInventors: Eiichiro Fujisaki, Koutarou Suzuki
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Patent number: 8458478Abstract: A signature is generated by a scheme in which x denotes a secret key of a signature generating apparatus, mrec?{0, 1}M denotes a recovery message, k denotes an arbitrary value, g denotes a generator of a cyclic group G of order q, R represents gk?G, H1 represents a hash function H1: {0, 1}*?{0, 1}L, H2 represents a hash function H2: {0, 1}*?{0, 1}M that has a variable output length, H3 represents a hash function H3: {0, 1}*?Zq, r=H1(R, mrec)|mrec(+)H2(R, H1(R, mrec)), where (+) represents an exclusive-OR operator, t is defined for ?, which depends on r, as t=H3(?), s is defined as s=k?t·x?Z, and a signature is ?=(r, s).Type: GrantFiled: April 24, 2008Date of Patent: June 4, 2013Assignee: Nippon Telegraph and Telephone CorporationInventors: Koutarou Suzuki, Masayuki Abe, Tatsuaki Okamoto, Atsushi Fujioka, Go Yamamoto
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Publication number: 20130114815Abstract: A sharing apparatus independently shares a value corresponding to each element ?(?, i, ?)·g2 of basis vectors bi*(?) among each subset SUB(?) consisting of H(?) share management apparatuses PA(?, 1), . . . , PA(?, H(?)) to generate share information SH(?, i, ?, ?, h(?)) corresponding to each element ?(?, i, ?)·g2. The share management apparatus PA(?, h(?)) generates a share secret value DSH(?, ?, h(?)) by performing a common calculation common in the subset SUB(?) on common information shared in the subset SUB(?) and the share information SH(?, i, ?, ?, h(?)). An acquisition apparatus generates reconstructed secret values SUBSK(?, ?) for each subset SUB(?) by performing a reconstruction processing for the subset SUB(?) and generates generation information D*(?) from the reconstructed secret values SUBSK(?, ?).Type: ApplicationFiled: July 22, 2011Publication date: May 9, 2013Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Ryo Nishimaki, Koutarou Suzuki
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Publication number: 20120163588Abstract: An information output apparatus identifies, according to a rule established for each of functional encryption protocols or a rule established for each combination of the protocols, one or more identifiers corresponding to a particular functional encryption protocol or a combination of the particular protocols, sets a particular piece of first correspondence information corresponding to the identifier or identifiers, and outputs first information which is a ciphertext or key information of the functional encryption scheme that corresponds to the particular piece of first correspondence information.Type: ApplicationFiled: July 30, 2010Publication date: June 28, 2012Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tetsutaro Kobayashi, Koutarou Suzuki
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Publication number: 20120027201Abstract: Security against CCA is improved without providing space for just improving the security against CCA in a ciphertext space. In encryption processing, a first ciphertext C1 is calculated from a plaintext M and a symmetric key K; a value containing a value corresponding to the symmetric key K and a value corresponding to the first ciphertext C1 is put into a collision-resistant function H to calculate a function value of the function H; and r corresponding to the function value is used to calculate second ciphertext C2=r·(??=1nv?·b?)+?·bn+1?G1n+1. In decryption processing, the second ciphertext C2?G1n+1 and key information D1*=?·(??=1nw?·b?*)+bn+1*?G2n+1 are put into a bilinear function e to calculate a function value S˜=e(C2, D1*)?GT; a value corresponding to the function value S˜ and the first ciphertext C1 are put into the collision-resistant function H to calculate a function value of the function H; and it is judged whether r˜ corresponding to the function value satisfies C2=r˜·(??=1nv?·b?)+?˜·bn+1?G1n+1.Type: ApplicationFiled: April 23, 2010Publication date: February 2, 2012Applicant: NIPPON TELEGRAPH AND TELEPHONE CORP.Inventors: Eiichiro Fujisaki, Koutarou Suzuki