公开(公告)号：US20220350638A1

公开(公告)日：2022-11-03

申请号：US17764977

申请日：2019-10-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Koki HAMADA

IPC: G06F9/46 ,  G06F17/10

Abstract: When an inside iterative calculation does not end after a predetermined number of iterations, a midway value of a loop variable is retained and a calculation of an output value is not performed in an outside iterative calculation. In addition, subsequently, execution of the iterative calculation is continued using the value of the loop variable having been retained when the inside iterative calculation is executed once again. In other words, in each iterative calculation, an object iterative calculation is only performed when all iterative calculations immediately inside the object iterative calculation have ended. Recursively performing these processing steps enables wasteful calculation in inside iterative calculations to be reduced.

公开(公告)号：US20220224516A1

公开(公告)日：2022-07-14

申请号：US17615106

申请日：2019-06-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Koki HAMADA

IPC: H04L9/08

Abstract: Division is realized with a small number of processing stages. A secure computation apparatus (1) obtains a secret value representing a result of divided N by D using a secret value [N] of a real number N and a secret value [D] of a natural number D. An initialization unit (12) sets a secret value [PL1] of a partial remainder PL1 to 0. A parallel comparison unit (13) computes secret values [E1], . . . , [ER−1] of comparison results E1, . . . , ER−1 of comparing a secret value [n] of a partial divisor n=Pj+1R+Nj with [D]×g for each integer g not less than 1 and less than R in parallel. An update unit (14) computes a secret value [Qj] of a quotient Qj and a secret value [Pj] of a partial remainder Pj that satisfy n=DQj+Pj using the secret values [E1], . . . , [ER−1] of the comparison results E1, . . . , ER−1. An iterative control unit (15) executes the parallel comparison unit (13) and the update unit (14) for each integer j from L1−1 to −L0.

公开(公告)号：US20210377005A1

公开(公告)日：2021-12-02

申请号：US17049340

申请日：2019-04-22

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Dai IKARASHI ,  Koki HAMADA

IPC: H04L9/08 ,  G09C1/00

Abstract: An aggregate median is efficiently obtained while confidentiality is kept. An order computing part generates ascending order a and descending order d within a group when a table which has been stably sorted based on a desired value attribute and a key attribute is grouped based on the key attribute. A subtracting part generates shares {a−d}, {d−a} of a−d, d−a. A bit deleting part generates shares {a′}, {d′} of a′, d′ obtained by excluding least significant bits from {a−d}, {d−a}. An equality determining part generates shares {a″}, {d″} of {a″}:={|a′=0|}, {d″}:={|d′=0|}. A format converting part (15) converts {a″}, {d″} into [a″], [d″]. A flag applying part generates shares [va], [vd] of [va]:=[v1a″], [vd]:=[v1d″]. A permutation generating part generates shares {{σa}}, {{σd}} of permutations σa, σd which sort ¬a″, ¬d″. A median computing part generates a share [x] of a vector x.

公开(公告)号：US20210182062A1

公开(公告)日：2021-06-17

申请号：US17267813

申请日：2019-08-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Dai IKARASHI ,  Koki HAMADA

IPC: G06F9/30 ,  G06F9/38

Abstract: A secure strong mapping computing system is a secure joining system including a plurality of secure computing apparatuses. The plurality of secure computing apparatuses include a first vector joining unit 11n, a first permutation calculation unit 12n, a first vector generation unit 13n, a second vector joining unit 14n, a first permutation application unit 15n, a second vector generation unit 16n, a first inverse permutation application unit 17n, and a first vector extraction unit 18n.

公开(公告)号：US20180025670A1

公开(公告)日：2018-01-25

申请号：US15541410

申请日：2016-02-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Dai IKARASHI ,  Ryo KIKUCHI ,  Koki HAMADA ,  Koji CHIDA

IPC: G09C1/00

Abstract: An inconsistency in shares is detected with a small volume of communications traffic. n inconsistency detecting devices generate random numbers si and make the random numbers si public. The n inconsistency detecting devices generate a common random number s which is the sum total of the random numbers s0, . . . , sn−1. The n inconsistency detecting devices calculate shares [c]i. The n inconsistency detecting devices generate shares [r]i, each of which would become a random number r by reconstruction. The n inconsistency detecting devices calculate shares [d]i, each of which would become a judgment value d by reconstruction. One inconsistency detecting device receives shares [d]1, . . . , [d]n−1 from n−1 inconsistency detecting devices. The one inconsistency detecting device restores n−k shares [d]′k, . . . , [d]′n−1 from k shares [d]0, . . . , [d]k−1. The one inconsistency detecting device judges, for j=k, . . . , n−1, whether or not a share [d]j and a share [d]′j coincide with each other.

公开(公告)号：US20230033922A1

公开(公告)日：2023-02-02

申请号：US17791547

申请日：2020-01-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Koki HAMADA ,  Ryo KIKUCHI

IPC: H04L9/08 ,  G06F7/544

Abstract: A secure maximum value computation apparatus, assuming that a set X={[[x1]], [[x2]], . . . , [[xn]]}, includes an output unit 1 that outputs [[x1]] and [[1]] as a maximum secret value [[y]] and a flag [[z(x1)]], respectively, when n=1 holds, a comparison unit 2 that computes a comparison result of which is larger with respect to a predetermined order for each pair {[[xi]], [[xj]]}⊂X of elements of the X, a flag computation unit 3 that computes whether all comparison results related to each of the [[xi]]s are “large” for each of the [[xi]]s to set a computed value as a flag [[z(xi)]], and a maximum value computation unit 4 that uses the [[z(xi)]] to computes a maximum value [[y]].

公开(公告)号：US20210314145A1

公开(公告)日：2021-10-07

申请号：US17267837

申请日：2019-08-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Dai IKARASHI ,  Koki HAMADA ,  Ryo KIKUCHI ,  Naoto KIRIBUCHI

IPC: H04L9/08 ,  G06F7/78 ,  G06F7/72 ,  G06F7/76

Abstract: A secure joining system is a secure joining system including a plurality of secure computing apparatuses. The plurality of secure computing apparatuses include a first vector joining unit, a first permutation calculation unit, a first vector generation unit, a second vector joining unit, a first permutation application unit, a second vector generation unit, a first inverse permutation application unit, a first vector extraction unit, a second permutation application unit, a third vector generation unit, a second inverse permutation application unit, a second vector extraction unit, a modified second table generation unit, a third permutation application unit, a fourth vector generation unit, a shifting unit, a third inverse permutation application unit, a bit inversion unit, a third vector extraction unit, a modified first table generation unit, a first table joining unit, and a first table formatting unit.

公开(公告)号：US20210287573A1

公开(公告)日：2021-09-16

申请号：US17055993

申请日：2019-05-20

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Koki HAMADA

IPC: G09C1/00 ,  H04L9/08

Abstract: Calculation time is reduced without degrading approximation accuracy in calculation of a complicated function through secure computation. A secret batch approximation system calculates a concealed text [z] of an approximate value z for a function value y satisfying yj=f(xj) by using a concealed text [x] of a value x as input. g is defined as a polynomial for approximating each section of m sections into which the function f is divided. A parameter acquisition unit acquires a concealed text [a] of a parameter a corresponding to the value x for each integer j that is not less than 1 and not more than n, where aj is defined as a parameter pi corresponding to a section Ri including a value xj. A polynomial calculation unit calculates a polynomial g([x], [a]) by using the concealed text [x] of the value x as input based on the concealed text [a].

公开(公告)号：US20210263921A1

公开(公告)日：2021-08-26

申请号：US17252290

申请日：2019-06-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Dai IKARASHI ,  Koki HAMADA

IPC: G06F16/2455 ,  G06F21/62

Abstract: A secure joining system is a secure joining system comprising a plurality of secure computation apparatuses; and the plurality of secure computation apparatuses are provided with vector joining parts 11n, first permutation calculating parts 12n, first permutation applying parts 13n, first vector generating parts 14n, second vector generating parts 15n, bit-flipping parts 16n, second permutation calculating parts 17n, second permutation applying parts 18n, third vector generating parts 19n, inverse permutation applying parts 110n, vector separating parts 111n, third permutation applying parts 112n, attribute value permutating parts 113n and fourth vector generating parts 114n.

公开(公告)号：US20210191927A1

公开(公告)日：2021-06-24

申请号：US17057120

申请日：2019-05-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Dai IKARASHI ,  Koki HAMADA

IPC: G06F16/242 ,  G06F16/2457 ,  G06F16/215

Abstract: To efficiently determine intermediate data for use with an aggregate function while keeping confidentiality, a bit decomposition unit generates a share of a bit string by bit decomposition and concatenation of key attributes. A group sort generation unit generates a share of a first permutation, which performs a stable sort of the bit string in ascending order. A bit string sorting unit generates a share of a sorted bit string obtained by sorting the bit string with the first permutation. A flag generation unit generates a share of a flag indicating a boundary between groups. A key aggregate sort generation unit generates a share of a second permutation, which performs a stable sort of the negation of the flag in ascending order. A de-duplication unit generates shares of de-duplicated key attributes. A key sorting unit generates shares of sorted key attributes by sorting the de-duplicated key attributes.