34 results about "Oblivious transfer" patented technology

A method, apparatus, and a computer readable storage medium having computer readable instructions to carry out the steps of the method for anonymous access to a database. Each record of the database has different access control permissions (e.g. attributes, roles, or rights). The method allows users to access the database record while the database does not learn who queries a record. The database does not know which record is being queried: (i) the access control list of that record or (ii) whether a user's attempt to access a record had been successful. The user can only obtain a single record per query and only those records for which he has the correct permissions. The user does not learn any other information about the database structure and the access control lists other than whether he was granted access to the queried record, and if so, the content of the record.

Provided is a privacy protection method based on location service in a scene of the Internet of Things (IOT). The privacy protection method based on the location service in the scene of the IOT comprises two privacy protection schemes according to the characteristics on the basis of the location service and the privacy protection level, namely an absolute privacy query scheme for a quite high security level and a query privacy scheme for a quite low security level. Through analysis of application scenes, the secure multi-party computation technology is integrated into IOT location privacy protection, by utilization of technologies such as adding random numbers, using dot product properties, and carrying out homomorphic encryption and oblivious transfer protocols, a dot which is nearest to a query input location in a database to be queried is calculated and found out, different levels of protection measures are taken according to the different application scenes, and therefore the effect that the privacy of query input, query results and contents of the database to be queried is protected is achieved in the absolute privacy protection scheme, and the privacy of the query input and the query results is protected in the query privacy protection scheme.

A method, article of manufacture and apparatus for performing private retrieval of information from a database is disclosed. In one embodiment, the method comprising obtaining an index corresponding to information to be retrieved from the database and generating a query that does not reveal the index to the database. The query is an arithmetic function of the index and a secret value, wherein the arithmetic function includes a multiplication group specified by a modulus of a random value whose order is divisible by a prime power, such that the prime power is an order of the random value. The secret value is an arithmetic function of the index that comprises a factorization into prime numbers of the modulus. The method further comprises communicating the query to the database for execution of the arithmetic function against the entirety of the database.

Methods and apparatus are provided for secure function evaluation for a covert client and a semi-honest server using string selection oblivious transfer. An information-theoretic version of a garbled circuit C is sliced into a sequence of shallow circuits C1, . . . Cn, that are evaluated. Consider any wire wj of C that is an output wire of Ci, and is an input wire of Ci+1. When a slice Ci is evaluated, Ci's 1-bit wire key for wj is computed by the evaluator, and then used, via string selection oblivious transfer (SOT), to obtain the wire key for the corresponding input wire of Ci+1. This process repeats until C's output wire keys are computed by the evaluator. The 1-bit wire keys of the output wires of the slice are randomly assigned to wire values.

Methods and apparatus are provided for secure function evaluation between a semi-honest client and a semi-honest server using an information-theoretic version of garbled circuits (GC). An information-theoretic version of a garbled circuit C is sliced into a sequence of shallow circuits C1, . . . Cn, that are evaluated. Consider any wire wj of C that is an output wire of Ci, and is an input wire of Ci+1. When a slice Ci is evaluated, Ci's 1-bit wire key for wj is computed by the evaluator, and then used, via oblivious transfer (OT), to obtain the wire key for the corresponding input wire of Ci+1. This process repeats until C's output wire keys are computed by the evaluator. The 1-bit wire keys of the output wires of the slice are randomly assigned to wire values.

The invention discloses an ECDSA digital signature method based on two-party collaboration. The method comprises the following steps: step 1), respectively generating corresponding signature public and private key pairs and other parameters by a signature party Alice and a signature party Bob participating in the collaborative signature; and step 2), collaboratively completing ECDSA signature by Alice and Bob, and finally outputting the signature (r,s). According to the ECDSA digital signature method based on the two-party collaboration provided by the invention, under the premise of ensuringthe security and the correctness, a signature process does not introduce high-overhead password operations such as homomorphic encryption, oblivious transfer and the like, so that a signature scheme achieves a good balance between the communication overhead and the computation overhead, and therefore the performance is remarkably superior to that of all existing ECDSA two-party collaborative digital signature methods.

A design method for a secure face authentication system based on a CNN feature extractor belongs to the field of biometric identification, and specifically relates to a method for extracting face features using CNN and encrypting them with Paillier algorithm and inadvertent transmission protocol. Compared with the SCiFi system, the present invention replaces manually extracted features with features learned automatically by CNN, and performs binarization to remove the influence of noise, and has higher authentication accuracy. The test authentication rate on LFW library view2 is 91.48%. During the entire authentication process, the server will not know any characteristic information of the requester, and can only receive the characteristic ciphertext information but cannot decrypt it. The client only knows whether the authentication is passed, and knows nothing about other information including the Hamming distance. This system uses 320bit features to represent a face picture, and the amount of feature data is reduced by 2 / 3 compared with the SCiFi system, so the time-consuming encryption and authentication is low and the real-time performance is high.

An embodiment of the present invention provides a computer implemented method for the transfer of private information of one user to another user—a primitive known as Oblivious Transfer. An output from a strong pseudorandom function generation (SPRFG) is calculated by a first user's computing module based on first and second parameters: the first parameter specifying one of two secret keys; the second parameter being a value selected within the domain of the SPRFG by the first user. The first user is prevented from reading or learning the stored two secret keys. The output is transmitted to a computer of a second user which generates first and second encrypted values that are each based on an inverse SPRFG calculation using the first and second secret keys, respectively, and corresponding private values of the second user. The encrypted values are sent to a first computer of the first user that calculates one of the private values using a mathematical computation based on the second parameter and the one of the first and second encrypted values that corresponds to the one of the first and second key used.