公开(公告)号：EP3261082A4

公开(公告)日：2018-07-25

申请号：EP16746580

申请日：2016-02-01

申请人： NIPPON TELEGRAPH & TELEPHONE

发明人： IKARASHI DAI ,  KIKUCHI RYO ,  HAMADA KOKI ,  CHIDA KOJI

IPC分类号： G09C1/00 ,  G06F21/64 ,  H04L9/08

CPC分类号： G09C1/00 ,  G06F21/64 ,  H04L9/085

摘要： An inconsistency in shares is detected with a small volume of communications traffic. n inconsistency detecting devices generate random numbers s i and make the random numbers s i public. The n inconsistency detecting devices generate a common random number s which is the sum total of the random numbers s 0 , ..., s n-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：EP3021518A4

公开(公告)日：2017-03-15

申请号：EP14838104

申请日：2014-08-21

申请人： NIPPON TELEGRAPH & TELEPHONE

发明人： KIKUCHI RYO ,  IKARASHI DAI ,  CHIDA KOJI ,  HAMADA KOKI

IPC分类号： H04L9/32 ,  G09C1/00 ,  H04L9/08 ,  H04L29/06

CPC分类号： H04L63/083 ,  G09C1/00 ,  H04L9/085 ,  H04L9/3226 ,  H04L2209/46

摘要： Even when an intermediate server exists, a plurality of servers simultaneously authenticates a user securely. A user apparatus 1 disperses a password w'. The user apparatus 1 obtains a ciphertext Enc US_i ([w'] i ), which is obtained by encrypting a dispersed value [w'] i . The intermediate server 2 transmits the ciphertext Enc US_i ([w'] i ) to an authentication server 3. The authentication server 3 decrypts the ciphertext Enc US_i ([w'] i ) to obtain the dispersed value [w'] i . The authentication server 3 determines a verification value q a_i (W) . The authentication server 3 obtains a ciphertext Enc WS_a_i (q a_i (W) ). The intermediate server 2 decrypts the ciphertext Enc WS_a_i (q a_i (W) ) to obtain the verification value q a_i (W) . The intermediate server 2 verifies whether a sum total of the verification values is equal to 0 or not. The authentication server 3 determines a verification value q a_i (a_j) . The authentication server 3 obtains a ciphertext Enc S_a_iS_a_j (q a_i (a_j) ). The authentication server 3 decrypts the ciphertext Enc S_a_iS_a_j (q a_j (a_i) ) to obtain the verification value q a_i (a-j) . The authentication server 3 verifies whether a sum total of the verification values is equal to 0 or not.

公开(公告)号：EP2947814A4

公开(公告)日：2016-11-09

申请号：EP14740216

申请日：2014-01-16

申请人： NIPPON TELEGRAPH & TELEPHONE

发明人： IKARASHI DAI ,  KIKUCHI RYO ,  HAMADA KOKI ,  CHIDA KOJI

IPC分类号： H04L9/32 ,  H04L9/06

CPC分类号： G09C1/00 ,  H04L9/004 ,  H04L9/008 ,  H04L9/0643 ,  H04L9/3242

摘要： The present invention can be efficiently applied to secure computation and can achieve a low probability of successful tampering. A tampering detection device includes a parameter storage storing a parameter ± ijk (i = 0, ..., q-1; j = 0, ..., q-1; and k = 0, ..., q-1) for uniformly mapping from a ring R to a ring R q , a division part 12 dividing N values a 0 , ..., a N-1 into sets of q values, starting from the first value, to generate value vectors A 0 , ..., A Á-1 , a generation part 14 generating a checksum c including addition and multiplication, where vector multiplication is a function f defined by the formula given below, and a verification part comparing a verification value generated by using the value vectors A 0 , ..., A Á-1 and vector multiplication which is the function f defined by the formula given below with the checksum c to determine whether or not any of the values a 0 , ..., a N-1 has been tampered with,. Here, N and q are integers greater than or equal to 2 and p is a minimum integer greater than or equal to N/q.

公开(公告)号：EP2667370A4

公开(公告)日：2015-03-04

申请号：EP12754230

申请日：2012-03-08

申请人： NIPPON TELEGRAPH & TELEPHONE

发明人： IKARASHI DAI ,  HAMADA KOKI ,  CHIDA KOJI

IPC分类号： H04L9/00 ,  H04L9/32

CPC分类号： G06F21/602 ,  H04L9/008 ,  H04L9/085 ,  H04L9/3218 ,  H04L2209/42 ,  H04L2209/46 ,  H04L2209/50

公开(公告)号：EP3206201A4

公开(公告)日：2018-06-06

申请号：EP15849344

申请日：2015-10-05

申请人： NIPPON TELEGRAPH & TELEPHONE

发明人： HAMADA KOKI ,  IKARASHI DAI ,  KIRIBUCHI NAOTO

IPC分类号： G09C1/00 ,  G06F9/44 ,  H04L9/28

CPC分类号： H04L9/0618 ,  G06F7/16 ,  G06F9/44 ,  G06F17/16 ,  H04L9/085 ,  H04L9/14 ,  H04L2209/46

摘要： Determination as to whether a nondecreasing sequence exists or not is efficiently made. A sorting part 10 sorts elements of a set P i in ascending order to generate vectors t i,i+1 and b i,i+1 . A merging part 20 generates vectors t 0,m and b 0,m by repeating the process of merging vectors (t i,j , b i,j ) and (t j,k , b j,k ) to generate (t i,k , b i,k ). A stable-sorting part 21 generates a vector e by coupling and stably sorting vectors b i,j and t j,k . A searching part 22 searches for sets of (», x, y) in which e[»] is b i,j [x] and e[» + 1] is t j,k [y] and generates a set X including all x and a set Y including all y. An extracting part 23 sorts t i,j [x] (x ˆˆ X) in ascending order to generate a vector t i,k and sorts b j,k [y] (y ˆˆ Y) in ascending order to generate a vector b j,k . If the length of a vector t 0,m is 0, a determining part 30 outputs a result of determination that indicates the absence of a nondecreasing sequence.

公开(公告)号：EP2669878A4

公开(公告)日：2014-10-08

申请号：EP12739361

申请日：2012-01-20

申请人： NIPPON TELEGRAPH & TELEPHONE

发明人： IKARASHI DAI ,  HAMADA KOKI ,  CHIDA KOJI

IPC分类号： G09C1/00 ,  G06F7/544 ,  H04L9/08

CPC分类号： G06F7/57 ,  G06F7/5443 ,  H04L9/085 ,  H04L2209/46