368 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 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 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 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 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 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 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.

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.

Embodiments are directed to secure configuration change at an edge device. A method includes receiving configuration change data at a device, the configuration change data associated with an encrypted authentication key; sending the configuration change data to a plurality of peer devices; receiving secret shares from a quorum of the peer devices, wherein each of the quorum of peer devices sends its respective secret share if it determines that the configuration change data complies with a configuration policy; constructing an decryption key using a quorum of the secret shares; decrypting the authentication key using the decryption key; and applying the authentication key to install the configuration change on the device. The method may further comprise determining, by the device, whether the configuration change data complies with the configuration policy; and constructing the encryption key using the quorum of the secret shares and a secret share stored on the device.

The invention discloses a multi-party cooperative charging load safety prediction method and system capable of resisting malicious behaviors, and the method comprises the steps: enabling a trusted third party to generate a global authentication key, a function key and a related random value, which are needed in a load prediction process, at an offline stage in a system initialization stage; the data owner splits the original power data into a plurality of parts and sends the parts to the server; the charging operator decomposes the load prediction model into a plurality of secret shares, and the secret shares are deployed on different server nodes respectively; the plurality of server nodes cooperatively execute a safety function protocol, complete a neural network reasoning process and send a load prediction result share to a power grid dispatching center; and the power grid dispatching center reconstructs the received load prediction result share to obtain a load prediction result. The method can support a plurality of participants, greatly reduces the calculation and communication overhead under the condition of guaranteeing high prediction precision, and can resist malicious behaviors of server nodes.

The invention relates to the technical field of federated learning, in particular to a federated learning security aggregation method based on vector space secret sharing, which comprises the following steps that: a client divides a local model gradient into a plurality of secret shares and distributes the secret shares to a plurality of servers; the server carries out aggregation operation on the secret share through a security computing protocol, wherein the aggregation operation comprises addition and multiplication operation; calculating the similarity between the clients based on the secret state data, and screening out a credible client set; and executing security aggregation on the gradient share of the trusted client, reconstructing a global model gradient and issuing the global model gradient. According to the method, client poisoning attacks can be resisted, server reasoning attacks can also be resisted, a federal learning global model security aggregation method is designed based on vector space secret sharing, and threats caused by server offline are reduced.

The invention provides a block chain privacy protection method and system based on dynamic threshold homomorphic encryption, and efficient encryption and flexible management of privacy data are realized by combining a Paillier semi-homomorphic encryption algorithm and a dynamic threshold secret sharing mechanism. The method comprises the following steps: generating a public key-private key pair and a threshold parameter set based on a large prime number, carrying out grouping encryption on privacy information to be protected, directly executing dynamic data updating in a ciphertext state by utilizing an addition homomorphic characteristic, then splitting a decryption key into share ciphertexts, and realizing decentralized key distribution and security recovery through threshold parameter constraint; for a participant adding or exiting event, a threshold parameter set is dynamically adjusted and a key rule is reconstructed, and an encrypted data set is synchronously updated to maintain consistency. Therefore, the flexibility and expandability of the block chain system are improved while the account book privacy and the network privacy are guaranteed.

The invention discloses an outsourcing multi-party computing method, device and system capable of identifying malicious behaviors. The method comprises the following steps: receiving a secret sharing share of original data sent by a data owner; verifying the multiplication triple; for addition and constant multiplication operation, performing addition and constant multiplication calculation locally according to the received secret sharing share and constant, and for multiplication, performing multiplication calculation according to the received secret sharing share and the triad passing verification; when intermediate data needs to be reconstructed, random numbers are used for blinding, a blinding result is reconstructed, and a malicious calculation party is identified according to a reconstruction result. The method pays attention to a specific scene, that is, an opponent decays a certain calculation party in a predetermined range, the scheme does not need complex technologies such as zero-knowledge proof, and calculation can be accelerated according to the property that the honesty of a semi-honesty party follows the protocol. The calculation scheme does not need to verify behaviors of all calculation parties and does not need complex technologies such as zero-knowledge proof.

A computer-implemented method of generating shares of a shared secret, wherein each of a group of participants has a respective first secret share of the shared secret, wherein the method is performed by a first participant of the group and comprises: generating a respective blinding share of a shared blinding secret, obtaining at least a threshold number of respective intermediary shares from each of the first group of participants, wherein each respective intermediary share is generated based on a respective blinding share and a respective first secret share; generating an intermediary value based on each of the obtained intermediary shares; and generating a respective second secret share of the shared secret, wherein the respective second secret shared is generated based on the intermediary value and the respective blinding share.

The invention discloses a privacy protection Skyline query method based on mixed secret sharing under cloud computing, and belongs to the field of cloud data security query. The method comprises the following steps: firstly, establishing a multi-dimensional data outsourcing service scene comprising a cloud server group, a data provider and a client; a data provider holds an original database, and data is sent to a cloud server group after being subjected to offline preprocessing; and then, the client locally encrypts a plaintext query into two secret shares through arithmetic secret sharing, the two secret shares are sent to the cloud server group, the communication overhead is transferred to an offline stage through a function secret sharing technology so as to realize efficient and safe skyline query, and then respective query result sets closest to private plaintext data are obtained. And finally, the cloud server group returns the stored result set to the client, and sums the two shares locally according to the arithmetic sharing property to reconstruct a plaintext result. According to the method, the privacy protection Skyline query efficiency in an actual wide area network environment is improved.

The embodiment of the invention discloses a federated learning method and device for a low earth orbit satellite network and electronic equipment. A specific embodiment of the method comprises the following steps: sending an initial global parameter to each participating satellite through a ground station; for each participating satellite, the following steps are executed: generating trained parameters based on local data collected by the participating satellite, initial global parameters and a preset model; performing secret sharing on the trained parameters to obtain a secret share parameter set; sending each secret share parameter to each aggregation satellite based on a preset safe path set; for each aggregation satellite, performing weighted summation on the secret share parameter from each participating satellite to obtain a weighted secret share parameter, and sending the weighted secret share parameter to a ground station; global training parameters are generated through the ground station according to the received weighted secret share parameters. According to the embodiment, the practicability and safety of federated learning in the satellite network are improved.

Systems and methods are disclosed herein for protecting data in a storage device by encrypting or decrypting the data with a Data Encryption Key (DEK). The storage device is communicatively coupled to a host and is locked with the host by secret sharing. In one example, the storage device comprises a Physically Unclonable Function (PUF) configured to, during a key generation phase of operation, generate a set of DEK responses based on a set of DEK challenges (chalDEK) and an assembler configured to obtain a set of SED DEK secret shares (SSSED) based on the first set of DEK responses, receive additional data, and assemble at least the set of SED DEK secret shares (SSSED) and the additional data to create a DEK master secret. The storage device also comprises a crypto module configured to receive a DEK based on the master secret and perform encryption and / or decryption of data using the DEK.