40 results about "Random oracle" patented technology

A method on a computing device for enhancing the memory and cognitive ability of a participant by requiring the participant to differentiate between rapidly presented aural stimuli. The method trains the time order judgment of the participant by iteratively presenting sequences of upward and downward formant frequency sweeps, in random order, separated by an inter-stimulus interval (ISI). The upward and downward formant frequency sweeps utilize frequencies common in formants, i.e., the characteristic frequency components common in human speech. Icons are associated with the upward and downward formant frequency sweeps to allow the participant to indicate an order in which the sweeps are presented (i.e., UP-UP, UP-DOWN, DOWN-UP, and DOWN-DOWN). Correct/incorrect selection of an order causes the ISI and/or the duration of the frequency sweeps to be adaptively shortened/lengthened. A maximum likelihood procedure may be used to dynamically modify the stimulus presentation, and/or, to assess the participant's performance in the exercise.

The present invention is aimed at the proposal of a limited blind signature system which is highly safe such that its safety can be proven without the assumption of a random oracle model. A signature presenting apparatus is supplied with a public key, a blind secret identifier, a blind public identifier, a blind signature, and a random number. A signature verifying apparatus outputs “valid” if the signature presenting apparatus is supplied with the data and otherwise outputs “invalid”.

The invention belongs to the technical field of cyberspace security and particularly relates to a PEKS (public-key encryption with keyword search) method for lattice-based cloud stored cyphertext data under standard model. The method of the invention has no need for a random oracle so that the security of the designed PEKS method can more truly reflected; a designed cryptographic algorithm is based on assumption of LWE (learning with errors) hard problems, quantum computer attacks can be resisted effectively. The method of the invention has a need for specifying a unique cloud server to perform testing and return corresponding search results, so that no malicious servers are able to execute search test operation, and malicious server attacks are partly avoided accordingly. In addition, the algorithm can ensure that cyphertext is undistinguishable. Furthermore, in keyword cyphertext generation phase, the method of the invention needs no computing of high-overhead modular exponentiation and bilinear pairing operation, but the computing of finite linear algebraic operation, and accordingly is highly worthy of practical application in post-quantum communication environments.

Systems, methods, and computing device readable media for implementing fast oblivious transfer between two computing devices may improve data security and computational efficiency. The various aspects may use random oracles with or without key agreements to improve the security of oblivious transfer key exchanges. Some techniques may include public/private key strategies for oblivious transfer, while other techniques may use key agreements to achieve simultaneous and efficient cryptographic key exchange.

An efficient and safe group signature scheme is provided. According to the present invention, an open unit is provided to not an issuer but an opener, and a data required for operating the open unit does not include a key pair of the issuer, so that it is possible to accurately operate the open unit even if the issuer generates the public key in an illegal manner. In addition, it is possible to prove that a key pair of a member cannot be counterfeited. It is possible to implement from a discrete logarithm assumption a feature that a cipher text, that is, a portion of a signature text can be decrypted only by the opener in a method which is the same as a method representing that an ElGamal crypto scheme is safe. In addition, it is possible to implement from a random oracle assumption a feature that a knowledge signature has an extractability in a method which is the same as a method proving that a Schnorr signature is safe.

The invention discloses a safe mode index outsourcing method and a safe mode index outsourcing system under a single malicious cloud server. The method comprises the steps as follows: step1, a user T calls a sub-program Rand for six times to obtain six random pairs; step 2, the user T splits a mode index which needs to calculate according to the random pairs returned by the sub-program Rand, and simultaneously, the user T selects a random value r and multiplies the index of the mode index by r to obtain a new mode index, and splits the new mode index; step 3, the user T requests a server U to separately calculate the values which needs to calculate after splitting; step 4, the user T multiplies a random value which is related to ua and which is remained by the T by a result which is related to the ua and which is returned by the server U, and multiplies the results for r times to obtain a verification result 1; and the user T multiplies a random value which is related to ura and which is remained by the T by a result which is related to the ura and which is returned by the server U to obtain a verification result 2; comparing the result 1 and the result 2, and judging that the server could accurately perform calculation if the result 1 and the result 2 are equal to each other.

Described is a system for biometric authentication. The system converts biometric data into a cryptographic key r′ using a reusable fuzzy extractor process having an underlying hash function modeling a random oracle model. The system allows access to secured services when a comparison of r′ to a previously computed cryptographic key r shows a match.

The invention discloses a method for efficient public key encryption with forward security. The method comprises the following steps that step 1, system initialization is conducted and a PK and an initial SK1 of a user are calculated; step 2, the secret keys are updated; step 3, a plaintext m is encrypted through the PK so that a CT of the plaintext m at the current period i can be obtained; step 4, the CT is decrypted through an SK i at the current time period i so that the plaintext m can be obtained. The method has the advantages that an encryptor only needs to own one cluster element so that a public key of each time period can be obtained through public information. In addition, the public keys can be identity information. On the basis, an encryption scheme based on the identity can be converted into a public encryption scheme with forward security and an efficient public key encryption scheme with forward security which achieves adaptive selection ciphertext security under a random prediction machine model is obtained.

The invention discloses an anti-leakage group key negotiation system and method in group communication. The system comprises n users. All users share the same password pw. The system has a continuouspost-event leakage prevention security model. The system specifically comprises protocol participants, an opponent and a random oracle. The protocol participants are online devices participating in aprotocol. The opponent is a probability polynomial time algorithm through which various attacks possibly occur in a network are simulated. The random oracle communicates with the opponent to simulateinformation possibly obtained by the opponent in the network. According to the system and the method, the system is initialized; each protocol participant carries out automatic computing; each protocol participant carries out combined computing; and each protocol participant generates a common session key. According to the system and the method, under the condition that leakage attacks are resisted, a group key is negotiated, so the system and the method have relatively high practicability; and a high quality key negotiation protocol based on password authentication is provided, so the efficiency of the scheme is improved.

Systems and techniques are provided for random oracles in open networks. A node computing device of an open network may choose a random secret. The random secret may be a numeric or alphanumeric value. The node computing device may distribute shares of the random secret to node computing devices that are members of essential subsets for the node computing device. The node computing device may receive a share of a random secret from a second node computing device. The node computing device may be a member of an essential subset of the second node computing device. The node computing device may sign a deterministic seed message using the share of the random secret received from the second node computing device to generate a signature share. The node computing device may reveal the signature share and may receive a random value in response.

The invention relates to the field of access authentication in the Internet of Vehicles, in particular to a distributed authentication method for the Internet of Vehicles based on the blockchain technology. The method comprises the steps that when access authentication is carried out on a vehicle identity in an Internet of Vehicles distributed authentication system, by taking high reliability and high efficiency of authentication as a principle on the premise of considering an edge node trust problem, an RSU spontaneously establishes an edge authentication chain through three-stage broadcast, so that the Internet of Vehicles is divided into a plurality of edge authentication areas; the RSU in the area realizes the rapid authentication of local vehicles through half-group characteristics of Chebyshev mapping; the RSU serving as a blockchain node stores the authentication record of the vehicle, and when the behavior of the vehicle changes, the local vehicle list is updated in time; and finally, the security of the proposed authentication scheme is proved by using a random oracle model. According to the invention, high-efficiency and high-reliability distributed access authentication can be realized on the premise of considering the RSU trust problem.

In accordance with an example aspect of the present invention, there is provided an apparatus comprising at least one receiver configured to receive, via a first channel, a secret value and an identifier of a local node and, via a second channel, a random value, and at least one processing core configured to cause transmission to the local node of a first message comprising a hash value, the hash value being derived based on a set comprising the secret value, the random value, and an instruction.

Described is a system for obfuscating a computer program. Sensitive data of an unprotected computer program is received as input. A random oracle is used to algebraically hide a set of polynomial-size point functions representing the sensitive data. The system outputs a set of obfuscated instructions internally hiding the sensitive data. The set of obfuscated instructions are used to transform the unprotected computer program into a protected, obfuscated computer program that is accepting of the set of polynomial-size point functions. The obfuscated computer program is written to a non-volatile computer-readable medium.

The invention discloses a certificateless public key searchable encryption method and a certificateless public key searchable encryption system. The certificateless public key searchable encryption method does not need to be based on a random oracle machine model; the system comprises a secret key generation center, a data sending end, a data receiving end and a cloud server, and the secret key generation center is responsible for generating part of private keys for the data sending end, the data receiving end and the cloud server; the data sending end is responsible for encrypting the data; the data receiving end is responsible for generating a trap door of a keyword to be retrieved; and the cloud server is responsible for storing and retrieving ciphertext data. Public and private key pairs are added to the data sending end and the cloud server, trap door transmission can be conducted through a public channel, attacks of keyword guessing can be resisted, the ciphertext data retrievalfunction is achieved, and meanwhile the indistinguishability of ciphertext data and the indistinguishability of a trap door are guaranteed.

The subject disclosure is directed towards a technology by which data is securely distributed using a homomorphic signature scheme and homomorphic network coding signature schemes. A homomorphic signature scheme for signing the data is based upon binary pairing with standard prime order groups. Sets of data are signed based upon dividing a larger block of data into smaller blocks, and separately signing each smaller block. The smaller blocks may be distributed to nodes of a network topology that are configured for network coding. In one alternative, the homomorphic signature scheme protects against changes to the block identifier. Proof data may be provided independent of a random oracle, may be provided by providing parameters for verification in a Groth-Sahai proof system, or may be provided by providing parameters for verification independent of a Groth-Sahai proof system.

The invention discloses a block chain-based data transaction verification and data ownership tracing method and system, and the method comprises the steps: enabling a data user to upload data to an IPFS server through a block chain transaction platform, and returning a data address; generating a data label by using a file anti-counterfeiting mechanism, and generating a data commitment by using a random oracle machine; uploading the data label of the current data when an arbitration request is initiated for the authenticity of the data; a random oracle machine is used for inquiring to obtain a data label released by the data user, a data label stored in the IPFS server is obtained according to the data address, consistency comparison is carried out on the data label uploaded by the data buyer and the data label released by the data user, and whether data counterfeiting exists in the data user and the data buyer or not is judged. Through the technical scheme of the invention, data transaction verification and data ownership traceability can be completed, and the problems of data falsification and data ownership loss of two data transaction parties are solved.