A plurality of anonymized publisher-user identifiers are received at a processor, and a plurality of anonymized advertiser-user identifiers are received from an advertiser at the processor. Without de-anonymizing any publisher-user identifiers in the received plurality of publisher-user identifiers and any advertiser-user identifiers in the received plurality of advertiser-user identifiers, the processor obliviously computes an intersection among the received publisher-user identifiers and the received ad-user identifiers to create an intersection set containing a plurality of advertiser-user identifiers matched with publisher-user identifiers.

The present disclosure involves systems, software, and computer implemented methods for a efficient distributed secret shuffle protocol for encrypted database entries using dependent shufflers. Each of multiple clients provides an encrypted client-specific secret input value. A subset of clients are shuffling clients who participate with a service provider in a secret shuffling of the encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations and different blinding values. A last protocol step includes using homomorphism, for each client, to perform computations on intermediate encrypted data to homomorphically remove a first blinding value and a second blinding value, to generate a client-specific rerandomized encrypted secret input value. As a result, the client-specific rerandomized encrypted secret input values are generated in an order that is unmapped to an order of receipt, at the service provider, of the encrypted secret input values.

The subject matter discloses computer-implemented method performed during a multi-party computation (MPC) process performed between multiple parties, said method comprising, the multiple parties executing a pre-processing phase and obtain values of correlated random variables to be used in an MPC process, the parties periodically verifying the correctness of the correlated random variables by exchanging information between the multiple parties, refreshing the values of the correlated random variables in each of the multiple parties, wherein no party of the multiple parties has access to values of the correlated random variables stored in another party of the multiple parties during the verifying and refreshing processes, the multiple parties using the correlated random variables during the MPC process after verifying a correctness of the correlated random variables.

To detect tampering in secure computation while maintaining confidentiality with a little communication traffic. A random number generation part (11) generates [{right arrow over ( )}r.sub.i], [{right arrow over ( )}s.sub.i]. A random number multiplication part (12) computes [{right arrow over ( )}t.sub.i]:=[{right arrow over ( )}r.sub.i{right arrow over ( )}s.sub.i]. A secret multiplication part (13) computes [{right arrow over ( )}z]:=[{right arrow over ( )}x{right arrow over ( )}y]. A random number verification part (14) discloses a p.sub.i,jth element of each of [{right arrow over ( )}r.sub.i], [{right arrow over ( )}s.sub.i], [{right arrow over ( )}t.sub.i] and confirms whether the element has integrity as multiplication. A random number substitution part (15) randomly substitutes elements in each of [{right arrow over ( )}r.sub.i], [{right arrow over ( )}s.sub.i], [{right arrow over ( )}t.sub.i] except for the p.sub.i,j-th element to generate [{right arrow over ( )}r′.sub.i], [{right arrow over ( )}s′.sub.i], [{right arrow over ( )}t′.sub.i]. A subtraction value disclosure part (16) computes [{right arrow over ( )}x−{right arrow over ( )}r′.sub.i], [{right arrow over ( )}x−{right arrow over ( )}s′.sub.i]. A verification value computing part (17) computes [{right arrow over ( )}c.sub.i]:=[{right arrow over ( )}z]−({right arrow over ( )}x−{right arrow over ( )}r′.sub.i)[{right arrow over ( )}y]−({right arrow over ( )}y−{right arrow over ( )}s′.sub.i)[{right arrow over ( )}r′.sub.i]−[{right arrow over ( )}t′.sub.i]. A verification value confirmation part (18) confirms that verification values c.sub.i are all zero.

Provided herein are system, methods and computer program products for identifying duplicate records stored in a database system, comprising: generating a plurality of encrypted match indexes for each of a plurality of records stored in the database system, each of the plurality of encrypted match indexes encrypts a value of each encryption enabled field of a respective one of the plurality of records defined by at least one match rule, creating a cluster of records comprising at least one set containing at least two records of the plurality of records, the at least two records having respective encrypted match indexes corresponding to the at least one match rule, causing identification of duplicate records in the at least one set according to detection of records of the at least one set having respective match indexes matching the at least one match rule, and outputting an indication of the identified duplicate records.

Disclosed embodiments relate to performing secure and flexible searches of encrypted data. Operations may include maintaining a database of a plurality of sets of encrypted data; receiving a transformed search query for the database, the transformed search query having undergone a transformation process at a client including: identifying a plaintext string in a search query at the client, applying the plaintext string to a language dictionary accessible to the client, receiving, based on the language dictionary, one or more plaintext search strings, and encrypting, at the client, the one or more plaintext search strings; and returning a result based on the transformed search query, the result being based on the encrypted one or more plaintext search strings.

The present disclosure involves systems, software, and computer implemented methods for a verifiable communication-efficient secret shuffle protocol for encrypted data based on homomorphic encryption. A service provider and multiple clients participate in a secret shuffle protocol of randomly shuffling encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations, different blinding values, and use of random secret-shares. A protocol step includes homomorphic operations to shuffle encrypted secret input values so that resulting encrypted secret input values are rerandomized and in a shuffled sequence that is unmapped to an order of receipt by the service provider of the encrypted secret input values.

A transaction consensus processing method for a blockchain is provided. A target node that initiates a proposition performs compression processing on proposed transaction data based on a compression algorithm, and fragments the compressed transaction data into a number of data fragments based on an erasure code algorithm. The method includes: receiving a data fragment of the transaction data that is sent by the target node in a unicast mode, data fragments sent by the target node to nodes in the unicast mode being different; broadcasting the received data fragment to other nodes, and receiving data fragments of the transaction data that are broadcast by the other nodes; performing data recovery on the received data fragment based on an erasure code reconstruction algorithm, performing decompression processing on the recovered transaction data based on a decompression algorithm to obtain original content of the transaction data, and completing the consensus.

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.

A Computer-implemented method is provided for encrypting data by a server in cooperation with a predetermined number of rate limiters. The method includes receiving, by the server, a user identification, and a password to be encrypted and creating a secret message, the secret message being a key suitable for use with a symmetric key encryption/decryption scheme. The method further includes generating, on the basis of a predetermined interactive cryptographic encryption protocol, a ciphertext which encrypts the user password, and the secret message using secret keys of the rate limiters of the subset, where the threshold is smaller than or equal to the number of rate limiters, and the protocol is adapted such that the server needs only to interact with a subset of the predetermined size of the number of rate limiters for decryption of the ciphertext to recover the secret message.