公开(公告)号：US20250023717A1

公开(公告)日：2025-01-16

申请号：US18765390

申请日：2024-07-08

Applicant: NEC Corporation

Inventor： Hikaru TSUCHIDA ,  Takuya HAYASHI ,  Toshiyuki ISSHIKI ,  Kengo MORI ,  Yukimasa SUGIZAKI

IPC: H04L9/08 ,  H04L9/00

Abstract: A distributed re-encryption apparatus comprises: a distributed re-encryption key storage part that stores shares obtained by secret-sharing a re-encryption key that re-encrypts a ciphertext into one encrypted with a different encryption key without decrypting the ciphertext; and a distributed re-encryption part that re-encrypts using the shares of the re-encryption key the ciphertext into one encrypted with a different encryption key without decrypting the ciphertext.

公开(公告)号：US20240356725A1

公开(公告)日：2024-10-24

申请号：US18685575

申请日：2021-08-31

Applicant: NEC Corporation

Inventor： Hiroto TAMIYA ,  Toshiyuki ISSHIKI ,  Kengo MORI ,  Haruna FUKUDA ,  Masahiro NARA

IPC: H04L9/06 ,  H04L9/08

CPC classification number: H04L9/0618 ,  H04L9/0869

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.

公开(公告)号：US20200177389A1

公开(公告)日：2020-06-04

申请号：US16468336

申请日：2016-12-15

Applicant: NEC Corporation

Inventor： Hikaru TSUCHIDA ,  Kengo MORI ,  Toshiyuki ISSHIKI

IPC: H04L9/32 ,  H04L9/08 ,  H04L29/08

Abstract: In IaaS (Infrastructure as a Service), when it is desirable to delegate the authority to a user outside a system, a recipient of an access token is designated, thereby preventing illegal distribution of the access token. There is provided an access token system including a generator and a verifier. The generator generates, using secret information of a recipient, a recipient-designated access token for which the recipient is designated, and provides the recipient-designated access token to a user. The verifier verifies that the user who makes access using the recipient-designated access token is the designated recipient.

公开(公告)号：US20190190702A1

公开(公告)日：2019-06-20

申请号：US16327383

申请日：2017-08-29

Applicant: NEC Corporation

Inventor： Toshiyuki ISSHIKI ,  Haruna HIGO ,  Kengo MORI

IPC: H04L9/08 ,  H04L9/32

CPC classification number: H04L9/088 ,  G06F21/62 ,  H04L9/08 ,  H04L9/32 ,  H04L9/3231 ,  H04L9/3236

Abstract: A data extraction system includes a registration apparatus, a data storage apparatus, and a query apparatus. The registration apparatus generates registration data including first information obtained by encrypting secret information, which is information that a user wishes to keep secret, by using a secret key and second information obtained by encrypting the secret key by using at least biological information of the user. The data storage apparatus holds the registration data. The query apparatus acquires the registration data by generating a query for acquiring the registration data from the data storage apparatus, extracts the secret key from the registration data by using biological information of the user, and extracts the secret information from the registration data by using the extracted secret key.

公开(公告)号：US20150334100A1

公开(公告)日：2015-11-19

申请号：US14652082

申请日：2013-12-13

Applicant: NEC CORPORATION

Inventor： Toshiyuki ISSHIKI ,  Toshinori ARAKI ,  Kengo MORI

IPC: H04L29/06

CPC classification number: H04L63/08 ,  G06F21/32 ,  H04L9/065 ,  H04L9/0866 ,  H04L9/3231 ,  H04L63/20

Abstract: A system includes a first bit string position permutation unit to perform position permutation of an input first bit string; a template generation unit to perform an exclusive OR operation of a bit string resulting from the position permutation of the first bit string and a code word of a binary linear code and generate auxiliary data; a second bit string position permutation unit to perform same position permutation of an input second bit string; and a bit string collation unit to verify that a hamming distance between position permutation result of the second and second bit strings is not more than a predetermined value.

Abstract translation: 系统包括：第一位串位置置换单元，用于执行输入的第一位串的位置置换; 模板生成单元，用于执行由第一位串的位置置换和二进制线性代码的代码字产生的位串的异或运算，并生成辅助数据; 第二位串位置置换单元，用于执行输入的第二位串的相同位置置换; 以及位串对照单元，用于验证第二和第二位串的位置置换结果之间的汉明距离不大于预定值。

公开(公告)号：US20240214178A1

公开(公告)日：2024-06-27

申请号：US18291341

申请日：2021-07-29

Applicant: NEC Corporation

Inventor： Hiroto TAMIYA ,  Toshiyuki ISSHIKI ,  Kengo MORI ,  Sanami NAKAGAWA

IPC: H04L9/00

CPC classification number: H04L9/008

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.

公开(公告)号：US20240171373A1

公开(公告)日：2024-05-23

申请号：US18283308

申请日：2021-03-23

Applicant: NEC Corporation

Inventor： Hiroto TAMIYA ,  Toshiyuki ISSHIKI ,  Kengo MORI ,  Sanami NAKAGAWA

IPC: H04L9/00 ,  G06F7/544

CPC classification number: H04L9/008 ,  G06F7/5443

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.

公开(公告)号：US20210374267A1

公开(公告)日：2021-12-02

申请号：US16322531

申请日：2017-08-07

Applicant: NEC Corporation

Inventor： Haruna HIGO ,  Toshiyuki ISSHIKI ,  Kengo MORI

IPC: G06F21/62 ,  G06F21/32 ,  G06F21/43

Abstract: An information processing device according the present invention includes: a memory; and at least one processor coupled to the memory. The processor performs operations. The operations includes: transmitting a first identifier and a second identifier, which is different from the first identifier and is included in identifiers transmitted to a data management device that stores data in association with an identifier of the data, to the data management device; and selecting the data related to the first identifier from the data related to the first identifier and the second identifier received from the data management device.

公开(公告)号：US20200322124A1

公开(公告)日：2020-10-08

申请号：US16305105

申请日：2017-06-01

Applicant: NEC Corporation

Inventor： Toshiyuki ISSHIKI ,  Haruna HIGO ,  Kengo MORI

IPC: H04L9/00 ,  H04L9/08 ,  G06F16/28

Abstract: An encrypted information matching device 20 includes: a storage unit 240 in which representative information representing a group based on similarity in a characteristic and encrypted information to be matched belonging to the group are associated with each other and stored; an identification unit 231 which calculates a first similarity between the encrypted input information and the representative information stored in the unit 240, and which, based on the first similarity, identifies a group to be matched with the first input information; and a determination unit 232 which calculates a second similarity between the encrypted input information and the encrypted information to be matched that belongs to the group identified, in a state in which the input information and the information to be matched are encrypted, wherein the unit 232 determines the presence or absence of information to be matched which makes the calculated second similarity satisfy criteria.

公开(公告)号：US20160105277A1

公开(公告)日：2016-04-14

申请号：US14786771

申请日：2014-04-23

Applicant: NEC CORPORATION

Inventor： Toshiyuki ISSHIKI ,  Kengo MORI ,  Toshinori ARAKI

IPC: H04L9/06 ,  H04L9/32

CPC classification number: H04L9/0618 ,  G06F21/62 ,  H04L9/008 ,  H04L9/3231 ,  H04L9/3239 ,  H04L9/3242 ,  H04L2209/24 ,  H04L2209/34

Abstract: An encrypted text matching system includes: an auxiliary data generating unit that generates first and second auxiliary data, which are for verification of matching between a first encrypted text that is obtained by encrypting at least one of a plurality of data segments into which input data is divided by segmenting unit and that is registered with a storage device and a second encrypted text that is obtained by encrypting at least one of a plurality of data segments into which input data to be matched is divided by segmenting unit, the verification being performed by using a Hamming distance between plaintexts; and a matching determining unit that takes a difference between the first and second encrypted text, and determines whether a Hamming distance between plaintexts that corresponds to the difference between the first and second encrypted text is equal to or less than a predetermined certain value.

Abstract translation: 加密文本匹配系统包括：辅助数据生成单元，其生成第一和第二辅助数据，用于验证通过加密输入数据的多个数据段中的至少一个获得的第一加密文本之间的匹配 由分割单元划分，并且通过对通过分割单元划分要匹配的输入数据的多个数据段中的至少一个进行加密而获得的存储装置和第二加密文本进行登记，所述验证是通过使用 明文之间的汉明距离; 以及匹配确定单元，其取得第一和第二加密文本之间的差异，并且确定与第一和第二加密文本之间的差异相对应的明文之间的汉明距离是否等于或小于预定的某一值。