52 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”.

A high-performance distributed ledger and transaction computing network fabric over which large numbers of transactions (involving the transformation, conversion or transfer of information or value) are processed concurrently in a scalable, reliable, secure and efficient manner. In one embodiment, the computing network fabric or “core” is configured to support a distributed blockchain network that organizes data in a manner that allows communication, processing and storage of blocks of the chain to be performed concurrently, with little synchronization, at very high performance and low latency, even when the transactions themselves originate from distant sources. This data organization relies on segmenting a transaction space within autonomous but cooperating computing nodes that are configured as a processing mesh. Each computing node typically is functionally-equivalent to all other nodes in the core. The nodes operate on blocks independently from one another while still maintaining a consistent and logically-complete view of the blockchain as a whole. According to another feature, secure transaction processing is facilitated by storing cryptographic key materials in secure and trusted computing environments associated with the computing nodes to facilitate construction mining proofs during the validation of a block.

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.

Embodiments described herein relate to systems and methods for transmitting service related messages, e.g., via a reverse push connection. In some embodiments, a UE may be configured to receive a random value from a server, the random value based at least in part on a capacity of the server and / or network. The UE may be configured to compare the random value to a generated value, and determine, based at least in part on the comparison, to transmit a service related message over a reverse push connection rather than via a hypertext transport protocol (HTTP) request. In some embodiments, the service related message may be any message that relates to a service available between devices, such as an identity (ID) query request, a service (de-) registration request, and / or a device listing request, among other types of messages.

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.

The application provides a generation method of a Fernet key in Keystone. The method comprises the following steps: sending a key generation instruction corresponding to a key request to a credible chip after receiving the key request of keystone; receiving a random value after the credible chip generates a random value according to a key generation instruction; returning the random value to the Keystone as the Fernet key. The credible chip is used as a random source of the Fernet key, the disadvantage of the existing system random source on the aspects of randomness and efficiency of generating a random value is solved, the randomness of the random value is improved, and the security and the working performance of the Fernet key are improved. The application further provides a generationsystem of the Fernet key in the Keystone, a computer readable storage medium and a server with above advantages.

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.

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.

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.

A method is provided for performing elliptic curve cryptography that reduces the number of required computations to produce, for example, a key pair. The number of computations is reduced by changing how a random nonce used in the computations is selected. In an embodiment, a look-up table is generated having pre-computed scalar values and elliptic curve points. Every time a new pseudo-random value is created for use in the ECDSA, a combination of the look-up table values is used to create multiple intermediate values. One of the multiple intermediate values is randomly chosen as a replacement value for one of the existing table entries. Each time the look-up table is used, multiple entries in the look-up table are updated to new look-up table values as described. In this manner, new randomness is provided in every step to generate the next pseudo-random nonce as a combination of multiple internally stored temporary look-up table values. Alternately, another mathematical group may be used.

The invention provides a safety analysis method based on a SelfTargetSIS problem. The method comprises the following steps: modeling a solution target of the SelfTargetSIS problem into explicit search on a message set, an allowable vector set and a challenge vector set; estimating a first search complexity in the classic model under a random oracle model; estimating a second search complexity in the quantum model under a random oracle model; and determining the minimum value of the first search complexity and the known classical optimal attack complexity as the effective attack complexity under the classical model, and determining the minimum value of the second search complexity and the known quantum optimal attack complexity as the effective attack complexity under the quantum model, thereby performing security evaluation on the anti-quantum signature. According to the method, an explicit search path based on a message set, an allowable vector set and a challenge vector set is supplemented and quantified, and the attack cost in the real world can be reflected more comprehensively.

Homomorphic attribute-based encryption (HABE) is a useful cryptographic primitive that supports both fine-grained access control and computation over ciphertexts. However, existing HABE schemes are limited to the homomorphic evaluation of circuits with either bounded depth or a restricted number of inputs. To address this problem, the present disclosure introduce a bootstrappable, fully homomorphic attribute-based encryption (FHABE) scheme that supports computations of circuits with unbounded depth over cross-attribute ciphertexts. Compared to state-of-the-art schemes, the proposed scheme also has a more lightweight ciphertext and eliminates the reliance on the random oracle model. Additionally, the present disclosure extend the FHABE to a proxy re-encryption setting, proposing an attribute-based homomorphic proxy re-encryption scheme that facilitates efficient sharing of encrypted data. This scheme is the first lattice-based multi-hop attribute-based proxy re-encryption scheme with unbounded hops of re-encryptions.

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-sizepoint 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 theunprotected 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 application discloses a kind of blockchain privacy query method and system based on inadvertent transmission technology, comprising: when user initiates blockchain data query, blockchain end and user end negotiate key by a kind of random oracle-based key exchange protocol, blockchain end uses key and returns data set ciphertext with obfuscated data to user, and user obtains data ciphertext and uses key only to decrypt the data required.This method can avoid the details of user query obtained by blockchain end, and at the same time, user cannot obtain plaintext data except target data, ensuring the privacy of blockchain data query.

The invention relates to a distributed digital signature suitable for a block chain environment, and discloses an identity-based threshold signature algorithm suitable for a block chain to support a password reverse firewall, which can prove that existence unforgeability security under adaptive selection message attack can be satisfied under a random oracle model. The method is characterized in that an identity-based threshold signature mechanism is adopted, so that the overhead of certificate generation, management and revocation in a traditional PKI system is avoided, and the method is suitable for a scene of direct binding of an identity and a key in a block chain. Besides, according to the algorithm, when the signature key and the random number are generated, a Shamir secret sharing technology is combined, so that an effective signature can be synthesized when the number of participating users reaches a preset threshold value, the system security is guaranteed, and fault tolerance and flexibility are enhanced. Meanwhile, a password reverse firewall (CRF) is introduced, privacy information is re-randomized in the signature process, information leakage attacks can be effectively resisted, even if secret keys of part of participants are leaked, the system can still keep overall safety and cannot be counterfeited for signature, and robustness and usability in a complex hostile environment are remarkably improved.

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.

The invention discloses a distributed key generation method, device and equipment, belongs to the technical field of distributed key storage and key management, and aims to solve the problems of leakage and loss of a private key of a block chain and insufficient security of a traditional management scheme. The method comprises the following steps: generating a public and private key pair in a chain relation when a secret key is initialized, performing distributed storage on a private key, a public key and an associated random number in the form of a secret share, and disclosing a commitment value; during transaction, selecting a preset number of nodes, converting a private key share into an additive share, cooperatively finishing threshold signature, and ensuring that the private key is not recovered to be complete; if the private key is leaked, a previous generation of private key share update is generated after verification of the preorder node; and if the share is lost, selecting nodes for joint sharing recovery. According to the method, a third-party authority is not needed, safety can be proved in a Random Oracle mode, and safety and availability are effectively balanced.

The present invention discloses an inter-group proxy re-encryption method capable of resisting selected ciphertext attack. A ciphertext is re-encrypted through proxy, a decryption capability is designated based on the group, and any member in the group can decrypt the ciphertext independently, so that the method is more flexible than an individual-based proxy re-encryption method. A reliable, convenient data sharing manner is provided for cloud storage. The calculation complexity of a licensor and a licensee is relatively low, and encryption and decryption can be performed conveniently. Particularly, compared with existing inter-group proxy re-encryption methods, the method has the advantage that the calculation complexity in the key generation phase is lower. A primary strong unforgeable signature is added when the ciphertext is generated, so that the ciphertext and the re-encrypted ciphertext cannot be tampered. Finally, if a dual linear Diffie_Hellman assumption is valid, the selected ciphertext attack is resisted in a random oracle model.

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.

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.