494 results about "Secret share" patented technology

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for batch retrieving data are described. In one aspect, a method includes receiving, from a client device and by a first multi-party computation (MPC) server of a cluster of MPC servers, a batch request for retrieving multiple database values stored in one or more databases. The batch request includes a first byte array that includes, for each requested key of multiple requested keys, a first secret share of the requested key. Each database includes multiple data items that each include a database key and a corresponding value. The MPC server processes each database key to generate first secret shares of matching data indicating whether the database key matches at least one requested key. The MPC server generates one or more results that represent database values corresponding to each database key that matches at least one requested key.

The invention discloses a self-random cross-chain dynamic cooperative supervision method based on zero knowledge proof, which is used for realizing safe and supervisible privacy protection transactions in a block chain cross-chain environment. The method comprises the following steps: dynamically screening users through MACRO credit scores to form supervision chains, the number of which is consistent with that of application chains, and generating public and private keys; deploying a contract and a ZKP circuit in each chain, wherein ZKP generation adopts self-random hash; according to the supervision chain secret key and the self-random hash, the transaction is encrypted, verified and signed, and a random block header and a transaction link are recorded in a linker (TEE); after the supervision chain verifies the signature, the transaction is linked and stored in a supervision chain Merkel mountain range, and a linker is updated at the same time; a supervision chain of any party puts forward a supervision application, and after the supervision application is agreed by the opposite party, two rounds of two-layer secret sharing technology collaboratively supervise the recoverable transaction. According to the method, self-random encryption, zero-knowledge proof and dynamic supervision mechanisms are fused, and multi-key supervision, self-random encryption key dynamic change and multi-supervision-chain dynamic cooperative supervision are realized.

The invention provides a medical data sharing method and system based on multi-party security computing, and the method comprises the steps: carrying out the credible access control of participants through zero-knowledge proof and biological feature authentication, and enabling the participants to comprise a medical institution, a medicine enterprise / research institution, a patient and a supervision institution; after credible access control is passed, when a medical institution extracts patient data, k-anonymity, differential privacy and homomorphic encryption technologies are utilized to encrypt and desensitize the extracted patient data and store the data to a block chain; receiving a calculation task request and calculation parameters published on the block chain by a medicine enterprise / research institution, realizing mixed circuit and secret sharing mixed multi-party security calculation by a calculation node based on an ABY3 framework, and verifying the compliance of a calculation result; and receiving a result verification and auditing request of the supervision mechanism, and if the calculation result is verified to be within an authorization range through the smart contract, allocating rewards to the medical mechanism, the calculation node and the block chain platform according to a preset proportion, thereby effectively improving the security and timeliness of medical data sharing.

The invention discloses an unmanned aerial vehicle group distributed management method based on a mobile active secret sharing technology, which supports off-line of a trusted institution and comprises the following steps: the trusted institution TA generates public parameters; a mobile base station MS and an unmanned aerial vehicle UAV participating in communication respectively register with a trusted mechanism in a registration stage, and acquire information such as a secret key and a certificate; the UAV joins the MS and is administered by the MS, and after mutual identity authentication, the MS distributes secret shares to the UAV; performing identity authentication on the unmanned aerial vehicle group; the unmanned aerial vehicles of the two groups share the share, group fusion is achieved, and after a new share is obtained, each unmanned aerial vehicle updates the certificate of the unmanned aerial vehicle. According to the method, the sub-secrets of the unmanned aerial vehicles are autonomously updated through a mobile active secret sharing technology, and fusion of completely decentralized unmanned aerial vehicle groups is realized. Secondly, an efficient certificate self-updating method is designed. The unmanned aerial vehicle can update the certificate only by calculating a threshold signature. Detailed safety certification and comprehensive experiments show that dynamic autonomous management of the distributed unmanned aerial vehicle group can be realized, and the method has good safety characteristics and relatively low calculation overhead.

The invention provides a threshold access system supporting threshold decryption and an NTRU type multi-party homomorphic encryption method, and belongs to the technical field of information security and data security. The threshold access system supporting threshold decryption comprises an initialization stage, a key generation stage, a secret share sharing stage, an encryption stage, a decryption stage, a homomorphic calculation stage and a data reconstruction stage, and a new NTRU type multi-party homomorphic encryption method is realized based on the threshold access system. Comprising an initialization stage, a key generation stage, an encryption stage, a decryption stage and a homomorphic calculation stage, so that the method can be more suitable for application scenarios of highly sensitive data processing, the dependence on a trusted third party is very small, the communication overhead and the calculation overhead are very small, the privacy of data is ensured, subdomain lattice attacks can be resisted, and the security of the data is improved. And the efficiency is relatively high.

The invention discloses an efficient secret state joint neural network inference method. The method comprises the following steps: S100, a data owner C and a model owner # imgabs0 # respectively send privacy data and a privacy model to computational nodes # imgabs1 # and # imgabs2 # in a secret sharing manner; s200, computing nodes # imgabs3 # and # imgabs4 # to run a secret state joint neural network reasoning algorithm, and respectively calculating secret shares Z0 and Z1 of reasoning results by sequentially executing secret state computing layer protocols, the secret state computing layer protocols comprising: S210: a secret state convolution layer algorithm # imgabs5 #; s220, a function layer algorithm # imgabs6 # is activated in a dense state; the invention further discloses an efficient dense state joint neural network inference system. According to the technical scheme, the ReLU algorithm with few communication rounds is designed based on the function secret sharing technology, so that the communication cost required for calculating the activation function is reduced, the convolutional neural network inference sub-protocol is designed by utilizing bilateral comparison and correct symbol discrimination, the inference accuracy is improved, and the inference result is consistent with a plaintext inference result.

The invention belongs to the field of passwords, and discloses an anti-quantum threshold digital signature method and system capable of tolerating high network delay. The method comprises the following steps: in a secret key generation stage, a trusted third party randomly selects a secret key and performs Shamir secret sharing on the secret key, and distributes a secret sharing value to each signer; in a distributed signature stage, each signer carries out packaging and secret sharing on a secret sharing value, a proving sub-circuit of a public key is operated based on a secure multi-party computing protocol, and each participant outputs a signature through two rounds of interaction. The anti-quantum threshold digital signature scheme has function interchangeability, that is, the signature generated by the threshold scheme and the signature generated by the original signature scheme can be verified by the same verification algorithm; meanwhile, the threshold digital signature scheme is efficient and achievable, and a threshold signature protocol in a scene of two parties of a wide area network only needs 2 seconds; moreover, the method has a better number of rounds, and the signature algorithm only needs two rounds.

The invention provides a decision tree security reasoning method and framework based on an efficient element selection protocol, and belongs to the technical field of data security processing. According to the method, nodes and user attributes of a decision tree are converted into two-dimensional matrix representation from one-dimensional vectors, and a constant round communication conversion protocol is designed based on function secret sharing, so that a ciphertext selection index is converted into two ciphertext one-hot vectors; and performing ciphertext dot product operation on the two-dimensional matrix and the two one-hot vectors to complete an element security selection function. After a one-dimensional vector is converted into a two-dimensional matrix, through ciphertext dot product operation, the communication size is not directly proportional to the number of nodes and the number of attributes any more and is only directly proportional to the square root of the number of elements. According to the method, a secure dot product and function secret sharing technology based on secret sharing is combined, the communication size is reduced to be in direct proportion to a square root from being in direct proportion to the number of nodes and the number of attributes, communication and calculation expenses are remarkably reduced, and an efficient privacy protection decision tree reasoning framework is provided.

The invention discloses a distributed key generation method and device based on an SM2 algorithm, a medium and equipment. The method comprises the following steps: determining a class group encryption key, a class group decryption key and a corresponding first zero knowledge proof through public parameters generated based on the SM2 distributed key; each participant shares respective secret share based on the class group encryption key, the class group decryption key and the first zero-knowledge proof, and creates a second zero-knowledge proof indicating that sharing is correct; each parameter party collects honest distribution shares and decryption shares based on the second zero knowledge proof, calculates a part of private keys and a part of public keys according to the decrypted secret shares, and creates a third zero knowledge proof indicating correct decryption; according to the third zero knowledge proof, partial public keys of participants correctly executing decryption operation are determined to reconstruct a global public key, the secret is shared by using a polynomial, each participant can contribute a part of shares, and a distributed secret key is generated without any credible setting.

This document describes systems and techniques for protecting the security of information in content selection and distribution. In one aspect, a method includes receiving, by a first computing system of MPC systems, a digital component request including distributed point functions that represent a secret share of a respective point function that indicates whether a user of the client device is a member of a first user group. Selection values are identified. Each selection value corresponds to a respective digital component, a set of contextual signals, and a respective second user group identifier for a respective second user group to which the respective digital component is eligible to be distributed. A determination is made, for each selection value and using the distributed point functions in a secure MPC process, a candidate parameter that indicates whether the second user group identifier matches a user group that includes the user as a member.

The invention discloses a privacy protection DBSCAN clustering method and device based on a secure multi-party computing environment. The method comprises the following steps that each data holder shares all data held by the data holder to three independent and non-collusive servers through a three-party copy secret sharing scheme; based on shared data held by the three servers, calculating distances among the data to obtain a distance matrix; after the distance matrix is converted into a Boolean matrix, a single-step density reachable matrix is further calculated; based on the single-step density reachable matrix, performing exponentiation operation and then further calculating the density reachable matrix; and obtaining a clustering result based on the density reachable matrix. According to the method, the expansion clustering step in the DBSCAN algorithm is realized by calculating the matrix multiplication, and the calculation efficiency of the DBSCAN clustering algorithm based on the secure multi-party calculation environment is effectively improved.

The invention provides a distributed function secret sharing key generation method aiming at the problems that an existing secret sharing key generation scheme depends on a trusted third party and does not support limitation of arithmetic sharing operation. The invention provides a solution for efficient distributed key generation based on improved function secret sharing between two communication parties. The protocol designed by the invention supports arithmetic sharing input and output, the calculation overhead and the communication overhead in the distributed key generation process are greatly reduced by optimizing the communication process on the premise of ensuring the safety and the accuracy of calculation, and the requirement on a trusted third party is completely removed by designing an efficient two-party calculation 2PC protocol, so that the communication efficiency is improved. A participant is allowed to directly generate keys for a distributed point function (DPF) and a distributed comparison function (DCF) through a two-party calculation protocol, the security and practicability of key generation are remarkably improved, and the method is particularly suitable for a scene without a trusted third party.

The invention relates to a DBSCAN classification method, device and equipment based on secret sharing privacy protection and a medium, and relates to a service party, a requesting party and three independent and non-collusion proxy computing parties, and the service party and the requesting party respectively have different characteristics of the same sample. The method comprises the following steps: a service party and a requesting party carry out secret sharing encryption on own sample characteristics and then send the sample characteristics to an agent calculation party; the agent calculation party calculates a reachable matrix and sends the calculated reachable matrix to the requester; and the requester executes a DBSCAN algorithm based on the reachable matrix to realize data classification. Compared with the prior art, the method has the advantages of good data security, high calculation efficiency and the like.

The invention relates to an anti-quantum distributed asynchronous random beacon method and system. The method comprises: a distribution stage of executing an anti-quantum asynchronous verifiable secret sharing method; an asynchronous common subset protocol is executed, distribution nodes corresponding to received effective secret shares serve as input, and a node set i with the size of t is consensus; executing a reconstruction stage of the anti-quantum asynchronous verifiable secret sharing method, reconstructing the secret value of each node in the set I, and if the reconstructed secret value is invalid, rejecting the node from the set I; and outputting the XOR sum of the secret values of the nodes in the set I as a public random number. According to the method, distributed generation of public random numbers is supported, the single-point fault problem is avoided, the system security can be ensured in an asynchronous network, and quantum computer attacks can be resisted.

The invention provides a privacy protection multi-task allocation method for an unmanned aerial vehicle crowdsourcing perception system, which combines addition secret sharing and homomorphic encryption to realize bilateral privacy protection of a task side and an unmanned aerial vehicle position. The task requester and the working party split a task position and a UAV departure position into two secret shares [.] 1 and [.] 2 by adopting an additive secret sharing mechanism respectively, and send the two secret shares [.] 1 and [.] 2 to the two independent service parties S1 and S2 respectively; the service party calculates an encrypted square Euclidean distance between the UAV and the task based on the shared share, and generates two distance matrix shares D1 and D2. On the basis, the two service parties cooperatively execute privacy comparison and a minimum index protocol under the optimized Paillier, and multi-task encryption shortest path distribution is realized in combination with a Hungary algorithm. According to the method, addition secret sharing is fused, Paillier encryption and task matching optimization are optimized, the total flight path of the UAV is remarkably reduced while position information privacy of the whole task allocation process is guaranteed, and good safety and deployability are achieved.

The embodiment of the invention provides a secret sharing and packaging method and device. And the plurality of participants respectively encode vectors formed by secret sharing of k pieces of data owned by the participants in a specified domain space to respectively obtain first domain elements owned by the participants, and the first domain elements have data structures meeting addition homomorphism. Then, the multiple participants perform secret sharing addition operation based on first domain elements owned by the multiple participants through first data interaction based on secure multi-party calculation, so that the multiple participants respectively obtain secret sharing of first sum values of the first domain elements owned by the multiple parties; the secret sharing of the first sum value is used as the secret sharing of a second domain element obtained by coding a vector formed by k data in a directional domain space.

The invention discloses an identity authentication method and system based on a national secret algorithm, and the method comprises the steps: building a hierarchical key management system based on a national secret IBE framework, generating a system master key pair through employing an SM2 algorithm, and achieving a decentralized key distribution mechanism; constructing a domain perception differential privacy protection module, defining a privacy budget allocation strategy according to the security level, and adding calibrated Laplace noise to the user identity feature vector; designing a distributed batch matrix multiplication protocol, and decomposing the distributed batch matrix multiplication protocol to a plurality of computing nodes for parallel processing through a secret sharing technology; a zero-knowledge proof verification mechanism is implemented, and identity verification is completed through a commitment scheme based on an SM3 hash algorithm; deploying a self-adaptive key updating strategy, and analyzing threat level change through a threat situation evaluation function; and establishing a secure communication channel based on SM4 symmetric encryption, and performing encryption processing by using the temporary session key. The security and expandability of the system are improved, the privacy of the user is effectively protected, and the system adapts to a dynamically changing network threat environment.

The present disclosure is directed to managing device authorization through the use of digital signature thresholds. Individual components of a device, or individual devices in a network environment, are associated with separate secret shares from which a digital signature can be derived. The digital signature may be used to authorize performance of a function. A threshold number of such secret shares are used in order to derive the digital signature. Therefore, an authorization process that relies on digital signature verification to determine that a function is authorized will do so if a threshold number of secret shares are available at authorization time.

The invention provides an NTRU-based batch on-loop multiplication triple generation method, which comprises the following steps of: firstly, designing a homomorphic encryption scheme based on a decision type NTRU difficulty problem, then providing a batch on-loop multiplication triple generation protocol of two parties, randomly selecting secret share vectors on integer rings by participants P0 and P1 of the protocol, and selecting lt by P0; gt; 0, lt; bgt; 0, P1 is selected as lt; gt; 1, lt; bgt; the method comprises the following steps: 1, generating an instantiated homomorphic encryption scheme by P0, generating two ciphertexts through packaging coding and encryption, sending a public parameter, a public key and the ciphertexts to another participant P1, selecting an n-dimensional random number vector r as a mask on a ring with a larger modulus by the P1, and calculating lt in an encryption state; gt; 0. Lt; bgt; 1 + 1t; gt; 1. Lt; bgt; the method comprises the steps that firstly, a ciphertext ctd of a vector a and a vector b is obtained, the ctd is sent to a participant P0, and after the participant P1 and the participant P0 execute homomorphic calculation and decryption operation through the packaging decoding and SIMD technology, the participant P0 obtains the share lt of the product of the elements of the vector a and the vector b; cgt; 0, the participant P1 obtains the other share lt of the product; cgt; 1. The scheme of the invention has higher calculation and communication efficiency, and has anti-quantum security.

The invention provides a sensitive data collaborative auditing platform and method based on multi-party network security computing, and relates to the technical field of multi-party security computing. The platform comprises a data input layer which is used for each data holder to acquire original data, standardize the original data, perform differential privacy processing on the standardized data, encrypt private data by adopting a Paillier homomorphic encryption algorithm to obtain a ciphertext, segment the ciphertext by adopting Shamir secret sharing to obtain a plurality of segment ciphertexts, uploading the fragmented ciphertext to a confusion layer; the confusion calculation layer is used for aggregating the fragmented ciphertexts to obtain aggregated ciphertexts, fragmenting the aggregated ciphertexts by adopting Shamir secret sharing to obtain a plurality of fragmented aggregated ciphertexts, and distributing the fragmented aggregated ciphertexts to audit layer nodes; performing target calculation on the fragmented aggregation ciphertext by adopting MPC calculation logic; and the auditing execution layer is used for converting the auditing rule into MPC computational logic. According to the application, the security, efficiency and cross-domain compatibility of multi-party collaborative auditing can be improved.

Methods and systems for securely generating secret shares in a distributed manner and distributing those secret shares to cryptographic devices are disclosed. The cryptographic devices can subsequently use these secret shares to perform threshold distributed cryptographic operations (such as encryption or decryption). A threshold number of generating cryptographic devices can each generate their own secret shares. These devices can also each generate partial secret shares that can be combined by receiving cryptographic devices to generate their own respective secret shares. Additionally, the generating devices can generate commitments corresponding to their secret shares. The generating devices can transmit the commitments to the other cryptographic devices and the partial secret shares to their corresponding receiving devices. At a later time, cryptographic devices possessing at least a threshold number of secret shares can collectively perform cryptographic operations using those secret shares.

The sender stores a pair of sender's public and private keys and a public key of the receiver, and carries out the steps of:A—generating a master key, that is a secret shared with the receiver, by key derivation from a current root key and using the sender's private key and the receiver's public key, and updating the root key with the generated master key;B—generating, by key derivation from said master key, a chain of message keys for securing messages to communicate to the receiver;C—generating a next pair of sender's public and private keys, sending the next sender's public key to the receiver and executing again the steps A andB using the next sender's private key and the same receiver's public key;wherein the current root key used in the step A isat a first iteration of step A, an initial root key prestored in the sender, said initial root key being a secret shared with the receiver, andat each subsequent iteration of the step A, the root key that has been updated at the preceding iteration of step A.

The invention provides an anti-key-leakage data secret state aggregation method and system in an electric power Internet of Things edge scene, and is applied to the technical field of electric power Internet of Things edges. The method comprises the following steps: sending an aggregation ciphertext to each target sensing terminal determined based on a secret sharing algorithm; receiving a sub-key corresponding to the secret sharing algorithm and sent by each target sensing terminal; if the number of the received sub-keys is greater than or equal to a preset threshold value of a secret sharing algorithm, decrypting the aggregated ciphertext based on the received sub-keys to obtain an aggregation result of the plaintext; the aggregated ciphertext is obtained by performing aggregation processing on an encryption result of homomorphic encryption on multi-dimensional user data sent by each sensing terminal by the edge Internet of Things agent, and the sub-key is determined by each target sensing terminal based on secret sharing of the obtained aggregated ciphertext and a pre-stored homomorphic encryption corresponding private key. According to the invention, the problems of system performance bottleneck and low security of user data existing in an electric power internet of things edge scene are solved.

The invention discloses a secure multi-party computing method and system based on secret sharing, and relates to the technical field of information security, and the method comprises the steps: obtaining original computing data, and dividing the original computing data into a plurality of data fragments; homomorphic encryption and symmetric encryption are respectively and sequentially carried out based on all the data fragments to obtain a plurality of layered encryption fragments; generating a random mask value and correspondingly binding the random mask value with the layered encryption fragment to obtain a final encryption fragment; based on all the final encryption fragments, distributing the final encryption fragments to each computing node for security computing, and correspondingly obtaining an intermediate result and a corresponding zero-knowledge proof; performing verification based on all zero-knowledge proof, and aggregating corresponding intermediate results based on verification results to generate an encryption calculation result; and decrypting based on the encrypted calculation result to obtain a plaintext calculation result. And the calculation efficiency is improved on the basis of ensuring the safety of the calculation data.

The embodiment of the invention discloses a safety calculation method and device for robot cluster collaboration and a medium, and relates to the technical field of safety calculation, and the method comprises the steps: carrying out the participant authentication of a robot cluster and a production enterprise node in advance, and carrying out the dynamic identity verification of each robot after the participant authentication is passed, the operation feature data of each target robot passing verification are extracted and encrypted, and encrypted feature vectors are determined; splitting the encrypted feature vector into a plurality of data fragments, storing the data fragments to a distributed node, obtaining a predetermined task cooperation strategy, and distributing the task cooperation strategy to an edge computing node in a secret sharing manner; executing safety calculation in a ciphertext state through a task cooperation strategy and the plurality of data fragments, determining a joint motion control instruction of each target robot, and generating corresponding zero-knowledge proof data; and after the verification is passed, the encrypted control instruction is distributed through the block chain smart contract, so that safety calculation of robot cluster collaboration is realized.

The invention relates to the technical field of privacy set intersection, and provides a two-party and multi-party privacy set intersection method based on casual key value storage and threshold secret sharing. According to the two-party privacy set intersection method, in order to judge whether an intersection cardinal number reaches a threshold value or not, OKVS is adopted to associate elements with secret sub-shares, when the number of the intersection elements reaches the threshold value, receiving is convenient, enough correct sub-shares can be obtained, then a secret value is reconstructed, and leakage of the intersection cardinal number is effectively prevented. Meanwhile, in order to avoid exponential-level combination among secret shares, a Reed-Solomon decoding algorithm based on fast Fourier transform is adopted to reconstruct a secret value. In addition, on the basis of two parties, an efficient multi-party privacy set intersection method is designed in combination with unconditional zero sharing. According to the method provided by the invention, the calculation complexity can reach # imgabs0 #, the linear communication overhead is kept, and the attack of a semi-honest enemy can be resisted.

Methods and devices that manage the secure distribution of credentials from a group of autonomous specialized nodes to a requesting node. The secure distribution of credentials may uses secret share and a group private key that none of the nodes reconstructs or possesses. The credentials include an identifier for the requesting node and a secret point that the node assembles from portions of the secret point provided by each of a plurality of the specialized nodes, where the secret point is based on the group private key and a map-to-point hash of the requesting node's identifier.

The invention discloses a privacy protection record linking method based on attribute encryption, which specifically comprises the following steps that: each data owner performs attribute classification on data, encrypts the data by using KeyGen, transmits the data to the data owner through a secure channel, encrypts the data based on attributes by using linear secret sharing, and finally stores the data on a cloud storage; the trusted authorization is responsible for recording public parameters and a master key, including attribute selection and storage and verification of a private key, so as to ensure that a data owner can consult and verify and prevent malicious behaviors; the data user obtains the decrypted ciphertext by matching the private key and linking the ciphertext after successful matching, and the method combines the record link with the attribute encryption, so that the calculation efficiency is improved while the data privacy is guaranteed, and the malicious collusion of the third party is effectively prevented.

The invention discloses a flexible and intelligent group key negotiation method under an unmanned aerial vehicle ad hoc network, which is applied to each unmanned aerial vehicle of an unmanned aerial vehicle group, the unmanned aerial vehicle has a secret share, the secret share is a univariate polynomial determined based on two threshold values, and the two threshold values are alternately updated during continuous group key updating. When the group key is updated at the current time, generating a new threshold value of a threshold value which is not updated when the group key is updated at the last time by adopting a threshold value decision model; according to the new threshold value, the updated threshold value when the group key is updated last time and the updated secret share when the group key is updated last time, the updated secret share when the group key is updated at the current time is determined; and according to the private key of the unmanned aerial vehicle and the updated secret share of the unmanned aerial vehicle when the group key is updated at the current time, determining secret data of the unmanned aerial vehicle, broadcasting and receiving secret data of other unmanned aerial vehicles, and calculating the group key at the current time according to the secret data. According to the invention, the threshold value can be changed flexibly, and the group key can be updated.

The invention discloses a privacy protection neural network reasoning method based on multi-point evaluation. According to the method, in the reasoning process of the privacy protection neural network, a given nonlinear function is constructed into a K-segment k-degree polynomial, a safe multiplication tree and a safe remainder tree are established, and then the remainder polynomial is safely evaluated. Due to the fact that the polynomial power needing to be evaluated in the online stage is reduced, the number of self-multiplication terms is reduced, the number of communication rounds of overall polynomial evaluation is reduced, the number of calling times of a secure multiplication triple in secret sharing is reduced, and the overhead of offline pre-calculation is correspondingly reduced. In addition, the hierarchical structure of the secure multiplication tree and the remainder tree supports multi-point input parallel computing, and the parallel computing capability of a modern multi-core processor or a GPU can be fully utilized.