Nippon Telegraph and Telephone Corporation

Casio Computer Co., Ltd.

Mitsubishi Electric Corporation

Ryo Kikuchi

Dai Ikarashi

Koki Hamada

Koji Chida

Gen Takahashi

Atsunori Ichikawa

Takayuki Semitsu

Hiroki Sudo

Satoshi Tanaka

Ibuki Mishina

Takamasa Nakao

Hitoshi Fuji

Tetsuya Okuda

Koutarou Suzuki

Toshifumi Kase

Naoto Kiribuchi

Naoto Yoshida

Koha Kinjo

Asami Miyajima

Carmen Kempka

A secure computation deviceof a secure computation system according to an aspect of this invention includes a first calculation unit, a second calculation unit, a third calculation unit, a fourth calculation unit, a fifth calculation unit, a sixth calculation unit, a seventh calculation unit, and an output unit. By calculation being performed in cooperation of these, a group by count operation can be performed on a table to which a flag is added.

Secret calculation system, apparatus, method and program

A server determines an array [[addr]] indicating a storage destination of each piece of data, generates an array of concealed values, and connects the generated array to the array [[addr]] to determine an array [[addr']]. The server generates a sort permutation [[σ]] for the array, applies the sort permutation [[σ]] to the array [[addr′]], and converts the array [[addr′]] into an array with a sequence composed of first Z elements set to [[i]] followed by αelements set to [[B]]. The server generates a sort permutation [[σ]] for the converted array [[addr′]], generates dummy data, imparts the generated dummy data to the concealed data sequence, applies the sort permutations [[σ]] and [[σ]] to the data array imparted with the dummy data, and generates, as a secret hash table, a data sequence obtained by deleting the last N pieces of data from the sorted data array.

Secret hash table construction system, reference system, methods for the same

The encrypted data analysis device includes a sorting unit that sorts by [Time Information] and then sorts by [User ID] an encrypted data set group including a plurality of encrypted data sets, each of the plurality of encrypted data sets including a [Location ID], the [User ID], and the [Time Information], an encoding unit that generates a [Flow], and encoding the [Location ID] extracted, and an equal sign determination unit that determines whether a [User ID] and another [User ID] adjacent to each other are equal, and when not equal, replaces a corresponding [Flow] with a [predetermined value that represents invalid].

Encrypted data analysis device, encrypted data analysis method, and program

The present invention provides techniques to calculate the number of surviving and the number of deaths while still concealing survival time data. The present invention includes: a group data position calculation means configured to calculate a share [[g]] of a sequence gand a share [[g]] of a sequence grepresented by predetermined equations from a share [[g]] of a sequence g of values of group of survival time data included in a survival time data set D; a group data number calculation means configured to calculate a share [[s]] and a share [[s]] from a share [[t]] of a sequence t of values of time of survival time data included in the survival time data set D, the share [[g]], and the share [[g]], by [[s]]=GroupSum ([[g]], [[t]]), [[s]]=GroupSum ([[g]], [[t]]); and a survival number calculation means.

Secret survival data processing system, secret survival data processing apparatus, secret survival data processing method, and program

A technique for performing secure computation of a sigmoid function with high speed and precision is provided. A secret sigmoid function calculation system is a system, in which g(x) is assumed to be a secure computable function, which calculates, from a share [[x]] of an input value x, a share [[σ'(x)]] of a value of a sigmoid function for the input value x, and includes: a first comparing means that generates a first comparison result [[c]]=less_than([[x]], t); a second comparing means that generates a second comparison result [[d]]=greater_than([[x]], t); a first logical computation means that generates a first logical computation result [[e]]=not([[c]]); a second logical computation means that generates a second logical computation result [[k]]=and([[c]], [[d]]) or [[k]]=mul([[c]], [[d]]); and a function value calculating means that calculates the share [[σ′(x)]]=mul([[k]], [[g(x)]])+[[e]].

Secret sigmoid function calculation system, secret logistic regression calculation system, secret sigmoid function calculation apparatus, secret logistic regression calculation apparatus, secret sigmoid function calculation method, secret logistic regression calculation method, and program

In a voting system including a vote broadcasting server and a plurality of client terminals, the vote broadcasting server generates a plurality of pieces of vote information that is data in which secret information is shared and transmits the vote information to each client terminal, each client terminal generates voting information by encrypting vote information such that the vote information can be decrypted when predetermined conditions are satisfied and transmits the voting information to the vote broadcasting server, the vote broadcasting server transmits a voting information group composed of voting information received from respective client terminals to the respective client terminals, and each client terminal ascertains a vote result according to the number of pieces of vote information decrypted from the voting information group and executes processing based on the vote result.

Voting system, vote relay server, client terminal, voting method, advertisement distribution system, and program

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.

Secure joining system, method, secure computing apparatus and program

A share generating device obtains N seeds s, . . . , s, obtains a function value y=g(x, e)∈Fof plaintext x∈Fand a function value e, and obtains information containing a member yand N−1 seeds s, where d∈{0, . . . , N−1} and d≠i, as a share SSof the plaintext x in secret sharing and outputs the share SS. It is to be noted that the function value y is expressed by members y∈F, . . . , y∈Fwhich satisfy m=m(0)+ . . . +m(N−1).

Share generating device, share converting device, secure computation system, share generation method, share conversion method, program, and recording medium

Provided is a technique for performing statistical processing such as processing for obtaining parameters of logistic regression analysis faster than before. A secure statistical processing system includes a cross tabulation table computing devicethat performs secure computation on a cross tabulation table in which frequencies are in plain texts while keeping each record concealed; and a statistical processing devicethat performs predetermined statistical processing using the cross tabulation table in which frequencies are in plain texts. The cross tabulation table computing devicemay include a plurality of secure computation devicesN that perform secure computation on a cross tabulation table in which frequencies are fragments subjected to secret sharing while keeping each record concealed, and a management devicethat restores the fragments to compute the cross tabulation table in which frequencies are in plain texts.

Secret statistical processing systems, methods, statistical processing apparatus and program

A share [x]of plaintext x in accordance with Shamir's secret sharing scheme is expressed by N shares [x], . . . , [x], and each share generating device Aobtains a function value r=P(s) of a seed s, obtains a first calculated value &#x3b6;=&#x3bb;(i, i(&#x2212;))[x]+rusing a Lagrange coefficient &#x3bb;(i, i(&#x2212;)), a share [x], and the function value r, and outputs the first calculated value &#x3b6;to a share generating device A. Each share generating device Aaccepts a second calculated value &#x3b6;, obtains a third calculated value z=&#x3bb;(i, i(+))[x]+&#x3b6;using a Lagrange coefficient &#x3bb;(i, i(+)), a share [x], and the second calculated value &#x3b6;, and obtains information containing the seed sand the third calculated value zas a share SSof the plaintext x in secret sharing and outputs the share SS.

Share generating device, reconstructing device, secure computation system, share generation method, reconstruction method, program, and recording medium

A power is computed at high speed with a small number of communication rounds. A secret computation system that includes three or more secret computation apparatuses computes a share [a] of the &#x3bd;-th power of data 'a' from a share [a] of data 'a' while data &#x201c;a&#x201d; is concealed. The share [a] of data &#x201c;a&#x201d; and an exponent &#x3bd; are input to an input unit (step S). A local operation unit computes the p-th power of a share [a] of the t-th power of data &#x201c;a&#x201d; without communication with the other secret computation apparatuses (step S). A secret computation unit uses secret computation that requires communication with the other secret computation apparatuses to compute a multiplication in which at least one of the multiplicands is the computation result of the local operation unit, to obtain the share [a] (step S). An output unit outputs the share [a] (step S).

Secret computation method, secret computation system, secret computation apparatus, and program

A secret computation system is a secret computation system for performing computation while keeping data concealed, and comprises a cyphertext generation device that generates cyphertext by encrypting the data, a secret computation device that generates encrypted basic statistics by performing secret computation of predetermined basic statistics using the cyphertext while keeping the cyphertext concealed, and a computation device that generates decrypted basic statistics by decrypting the encrypted basic statistics and performs predetermined computation using the decrypted basic statistics.

Secret computation system and method

A secure computation device obtains concealed information {M(i, . . . , i)} of a table M(i, . . . , i) having one-variable function values as its members. It is to be noted that M(i, . . . , i) generated by substituting counter values i, . . . , iinto the table M(i, . . . , i) represents a matrix M, which is any one of M, . . . , M. The secure computation device obtains concealed information {M} by secure computation using concealed information {i}, . . . , {i} and the concealed information {M(i, . . . , i)}, and obtains concealed information {M} of a matrix M, which is obtained by execution of a remaining process including those processes among a process P, a process P, a process P, and a process P, that are performed subsequent to a process P.

Secure computation device, secure computation method, program, and recording medium

Pand Phave stored a&#x2208;{a, a, a} and b&#x2208;{b, b, b} therein, and Pand Phave stored a&#x2208;Aand b&#x2208;Btherein. Here, P&#x2212;P, P=P, and a and b are arbitrary values and satisfy a=a+a+aand b=b+b+b, where Ais a complement of ain {a, a, a} and Bis a complement of bin {b, b, b}. Pand Pshare r, Pand Pshare r, and Pcalculates c=(a+a)(b+b)&#x2212;ab+r&#x2212;r. Psends cto P.

Secure computation system, secure computation apparatus, secure computation method, and recording medium

A share generating device obtains N seeds s, . . . , s, obtains a function value y=g(x, e)&#x2208;Fof plaintext x&#x2208;Fand a function value e, and obtains information containing a member yand N&#x2212;1 seeds s, where d&#x2208;{0, . . . , N&#x2212;1} and d&#x2260;i, as a share SSof the plaintext x in secret sharing and outputs the share SS. It is to be noted that the function value y is expressed by members y&#x2208;F, . . . , y&#x2208;F, which satisfy m=m(0)+ . . . +m(N&#x2212;1).

Growing community of inventors

Musashino, Japan

Ryo Kikuchi