A system and method for securing application programming interface (API) requests using multi-party digital signatures. The method includes generating, by a first system, at least one first secret share of a plurality of secret shares based on an API secret, wherein the plurality of secret shares includes the at least one first secret share and at least one second secret share, wherein the at least one second secret share is generated by at least one second system; and signing, by the first system, an API request using the at least one first secret share, wherein the API request is further signed by the at least one second system using the at least one second secret share, wherein the API request is signed without revealing any of the at least one first secret share to the at least one second system and without revealing any of the at least one second secret share to the first system.

A secure computation server includes: a computation processing part that performs secure computation by using data x received from a client and computes a computation result R; and a trail registration part that makes a predetermined trail storage system to store first trail data for certifying identity of the data x, the first trail data having been calculated from the data x, and second trail data for certifying a relationship between the data x and the computation result R. The predetermined trail storage system manages the first and second trail data in a non-rewritable manner and provides the first and second trail data to a predetermined audit node.

In a system having a plurality of servers, a method is executed to perform an encryption scheme. The method includes a server of the plurality of servers receiving a request token to compute a function on a data point, the data point being encrypted as a ciphertext and the request token being based on the ciphertext and the function. The server grants the request to compute the function on the datapoint by sending a function evaluation key, and participates in a distributed decryption protocol for determining a result of computing the function on the data point by sending a master secret key.

A computing system retrieves a credit check algorithm. The credit check algorithm utilizes one or more parameters for evaluation of a credit score of an individual. The computing system identifies a plurality of entities contributing parameters for the evaluation of the credit score of the individual. The computing system compiles the credit check algorithm into a plurality of components. Each component corresponds to a respective entity of the plurality of entities and each component generates an output unique to the respective entity. The computing system transmits each component to a respective entity of the plurality of entities. The computing system instructs each entity to share a respective output with each remaining entity. The computing system receives a credit score for the individual from each of the plurality of entities. Each credit score received from each entity is the same.

Developing a cyber security protocol to enable two members of a community to conduct a conversation without revealing neither their identity, nor the fact that a conversation took place. Secret randomized matching is used to allow people to claim certain personal attributes like age, place of residence, having a license, but without exposing their individual identity.

Embodiments of the present disclosure provides protocols, methods and systems which provides advantages such as the resistance of centralisation of mining on a blockchain network, preferably a Proof-of-Work blockchain. A method in accordance with an embodiment may comprise generating a plurality of non-parallelisable challenges (or “puzzles”) and allocating one of said plurality of challenges to each miner on the network. The miner uses an inherently sequential (non-parallelisable) algorithm to find a solution to his allocated challenge. The challenges are generated by a committee of nodes, and a new set of challenges is generated for each block.

A bit-decomposition secure computation apparatus uses r1, r2, and r3 satisfying w=r1+r2+r3 mod 2{circumflex over ( )}n as share information of (2, 3) threshold type RSS (Replicated Secret Sharing) stored in a share value storage apparatus, and includes an addition sharing part that sums two values out of the share information by modulo 2{circumflex over ( )}n arithmetic and distributes the sum using (2, 3) type RSS; and a full adder secure computation part that adds the value generated by the addition sharing part by distributing the sum of the two values to share information of one remaining value other than the two values used by the addition sharing part for each digit by using secure computation of a full adder.

Privacy protection methods, systems, and apparatus, including computer programs encoded on computer storage media, are provided. One of the methods is performed by a first computing device and includes: obtaining a plurality of object IDs, wherein the plurality of object IDs include a target object ID; sending the plurality of object IDs to a second computing device storing a plurality of pieces of data respectively associated with the plurality of object IDs for the second computing device to generate a plurality of ciphertexts respectively based on the plurality of pieces of data; and executing a cryptography protocol with the second computing device to obtain a ciphertext corresponding to the target object ID from the plurality of ciphertexts generated by the second computing device, wherein the target object ID is unknown to the second computing device.

Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media for secure collaborative computation of a matrix product of a first matrix including private data of a first party and a second matrix including private data of the second party by secret sharing without a trusted initializer. One method includes obtaining a first matrix including private data of the first party; generating a first random matrix; identifying a first sub-matrix and a second sub-matrix of the first random matrix; computing first scrambled private data of the first party based on the first matrix, the first random matrix, the first sub-matrix, and the second sub-matrix; receiving second scrambled private data of the second party; computing a first addend of the matrix product; receiving a second addend of the matrix product; and computing the matrix product by summing the first addend and the second addend.

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 [P.sub.L1] of a partial remainder P.sub.L1 to 0. A parallel comparison unit (13) computes secret values [E.sub.1], . . . , [E.sub.R−1] of comparison results E.sub.1, . . . , E.sub.R−1 of comparing a secret value [n] of a partial divisor n=P.sub.j+1R+N.sub.j 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 [Q.sub.j] of a quotient Q.sub.j and a secret value [P.sub.j] of a partial remainder P.sub.j that satisfy n=DQ.sub.j+P.sub.j using the secret values [E.sub.1], . . . , [E.sub.R−1] of the comparison results E.sub.1, . . . , E.sub.R−1. An iterative control unit (15) executes the parallel comparison unit (13) and the update unit (14) for each integer j from L.sub.1−1 to −L.sub.0.