94 results about "Distributed key generation" patented technology

A computer-implemented method and system for privacy-preserving location verification in distributed networks comprises initializing a multi-modal biometric authentication system on a user device, generating cryptographic keys using a distributed key generation protocol, binding the cryptographic keys to biometric templates using a fuzzy vault scheme, constructing and broadcasting encrypted location beacons, and generating zero-knowledge proofs of location claims. The system includes user devices equipped with biometric sensors and verifier devices configured to validate location claims and maintain consensus in a blockchain network. The method implements real-time liveness detection for multiple biometric input types, executes fault-tolerant consensus algorithms with privacy preservation, and maintains a dual-scoring mechanism comprising device trust scores and user reputation scores. The system enables secure location verification while preserving user privacy through cryptographic protocols and biometric authentication in decentralized environments.

The invention discloses a multi-party collaborative signature management method and system based on a key segmentation technology, and relates to the technical field of fragmentation encryption, and the method comprises the steps: initializing data in an encryption system, collecting behavior data when a key anomaly occurs in history, deploying an AI anomaly detection model, generating a master key through a distributed key generation protocol, and generating a multi-party collaborative signature in the encryption system; deriving time by using a hierarchical deterministic algorithm, segmenting a master key to form key fragments, and distributing each fragment to different nodes; formulating a periodic rotation triggering mechanism; calculating an abnormal score of each node, judging whether each node has an abnormal risk or not, and marking the abnormal risk; for the marked nodes with the abnormal risk, fragments are redistributed for alternation; dynamically adjusting the threshold according to the abnormal score; a client initiates a signature request, abnormal nodes are eliminated, fragment node aggregation is screened, and collaborative signature is carried out.

System and method of creating a multi-party computation (MPC) cryptographic signature for a blockchain based computer network, including: generating at least one first share and second share of a cryptographic key, based on a distributed key generation MPC protocol, signing a received message with the at least one first share, receiving the message signed with the at least one first share, signing the message signed with the at least one first share with the at least one second share, sending the message signed with the at least one second share and the at least one first share to a full node of the computer network, and adding a transaction to a ledger of the computer network, in accordance with the received message signed by the at least one first share and the at least one second share.

The invention provides a digital asset decentralized management method and system, and the method comprises the steps: enabling legal members in a group to jointly participate in the generation of an initial authorization key according to a preset distributed key generation protocol, dividing the key into a plurality of fragments through a threshold key sharing scheme, and storing the fragments in different member nodes; after the consensus is reached, the member node reconstructs a complete authorization key according to the request content, signs the key by adopting an aggregation signature scheme, generates an authorization certificate, and returns the certificate to the request node; a key cache mechanism is introduced, a member node maintains a local cache and stores historical authorization keys in the latest period of time, when a new authorization request is processed, available keys are searched from the local cache, and the available keys are directly used if hit.

The invention relates to the fields of cryptographic algorithms and homomorphic encryption, in particular to an anti-quantum-attack homomorphic encryption method. Along with increasing demands of outsourcing computing and privacy protection application in a multi-user scene, multi-key homomorphic encryption becomes an important research direction. The construction of a traditional multi-key homomorphic encryption scheme generally depends on a common random character string (CRS) model, and a trusted party needs to generate a common parameter for a public key so as to support calculation on a joint ciphertext. Due to the dependence on the central trusted mechanism, the anti-attack capability and the decentralization characteristic of the system are greatly reduced. In order to avoid excessive dependence on trusted third parties and public parameters, a distributed key generation protocol is used in the invention, all users are enabled to independently generate keys thereof, and ciphertexts of a plurality of users are expanded to the same dimension through a ciphertext expansion technology, so that the encryption efficiency is improved. Therefore, multi-key homomorphic encryption in a multi-user scene is realized without depending on a trusted third party, a lattice-based CRS-free multi-key homomorphic encryption method is provided, and the security and decentration characteristic of the scheme are enhanced. Furthermore, the invention provides a directional decryption mechanism and introduces the directional decryption mechanism into the scheme, the public key information of the target user is embedded into the ciphertext, it is ensured that only the specific target user can decrypt the ciphertext after homomorphic operation, and more flexible privacy protection is provided.

A method for implementing a distributed threshold signature, comprising: a distributed key generation stage: each of n participants generates a respective secret key share by means of a distributed key generation protocol, generates a respective homomorphic encryption public and secret key pair, and sends a homomorphic encryption public key to other participants; an offline stage: at least t+1 participants generate respective first random values and second random values, the participant also use homomorphic encryption algorithms of the homomorphic encryption public and secret key pairs, obtain coordinate components by means of an offline stage protocol and the second random values, and obtain secret key share component masked values on the basis of the respective secret key shares; and an online stage: the at least t+1 participants use the respective first random values, the secret key share component masked values, and the coordinate components to sign a same message in the online stage to obtain at least t+1 signature shares.

Systems and methods for distributed key generation is provided. In some embodiments, a public key and a private key are generated using elliptical curve cryptography (ECC) at a group of trusted parties. In some cases, an elliptical curve digital signature algorithm may be employed. Each party also generates a commitment and a blinding factor. The blinding factor may be a randomized polynomial integer. The parties use the commitments from the other parties to validate the public keys before receipt and combining the public keys into a group / aggregate public key. Content encryption keys (CEK) are then encrypted at each of the trusted parties using these aggregate public keys to generate wrapped content encryption keys (WCEK). Private keys are sharded and a sharded private key is generated at each party using the pieces of shards received by the trusted party. Subsequently, criteria may be received that allows for the release of these sharded private keys back to a trusted environment / enclave.

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.

The invention discloses a digital artwork anti-plagiarism method based on an alliance chain and decentralized identity authentication, and the method comprises the steps that participants send requests of registering as nodes of the alliance chain on an intelligent contract, the participants comprise a digital artwork market and users in the digital artwork market, and the requests of the participants comprise identity information of the participants; the alliance chain and the trusted third party verify whether the participant meets the condition of becoming an alliance chain node, and if yes, the alliance chain locally generates a public key and a private key at the node meeting the condition through a distributed key generation mechanism; according to the digital artwork anti-plagiarism method based on the alliance chain and the decentralized identity authentication, sharing and intercommunication of information of each node and digital artworks are realized through the alliance chain, and an information island is broken; the identity of the same to-be-verified person and the digital artwork are verified through the multiple nodes in the alliance chain, the transparency of digital artwork transaction is improved, and the possibility of plagiarism is reduced.

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.

A method for implementing a distributed digital certificate, comprising: each of n parties generating a respective threshold secret key share by means of a distributed key generation protocol; each of at least t+1 of the N parties generating a random value by means of an offline phase protocol; each of the at least t+1 parties receiving a certificate application, and signing application information in the certificate application by means of an online phase protocol and on the basis of the threshold secret key share and the random value generated by means of the offline phase protocol, so as to generate a certificate share; and after obtaining at least t+1 certificate shares, any one of the parties aggregating the at least t+1 signature shares into a total certificate.

System and method for executing scalable maliciously secure threshold Paillier cryptosystem. Distributed key generation includes generating Paillier public key N including bi-pnme modulus N=PQ, for large primes P, Q, such that; P = Q = 3 mod. 4; GCD(P --- 1, Q — 1) = 2; and GCD(N,Ø (N)) = 1, and generating Shamir secret sharing over integers of Paillier private key d satisfying; d = 0 modØ(N) and GCD(d, N) = 1. Public key N may be used to encrypt message to produce a ciphertext and / or to apply homomorphic evaluation of a linear function on a group of ciphertexts. Decryption includes generating at least one decryption share ctj = ctdj of a ciphertext (cr) from at least one respective party Pj, where ct is in Z*N2, and. private key d. After collecting a threshold of valid, t out of n generated decryption shares, ciphertext is decrypted to produce a plaintext by performing a reconstruction of the Shamir secret sharing in the exponent.

Systems and methods are disclosed for security through multi-party computation (MPC). In some examples, a system generates, at a first device and using a first private key share (of a plurality of private key shares). The plurality of private key shares each correspond to different devices. The system receives, from one or more additional devices, one or more additional partial signatures that are generated using one or more additional private key shares (of the plurality of private key shares). The system identifies that a total amount of partial signatures associated with the transaction is meets or exceeds a minimum threshold amount of partial signatures. The system aggregates the first partial signature and the one or more additional partial signatures to generate a signature, and facilitates processing of a transaction using the signature and a distributed ledger.

The invention belongs to the technical field of intelligent traffic system data privacy protection, and discloses a traffic flow federated security prediction method based on distributed homomorphic encryption, and the method comprises the steps: constructing a vehicle-road cloud integrated network architecture, constructing a local model and a global model based on LSTM, and forming a federated model; cooperatively generating a distributed key based on a road infrastructure node and a cloud platform node, and performing homomorphic encryption and training on the federated model; and traffic flow prediction is carried out based on the trained federal model. According to the method, the confidentiality of the model training process is higher, the confidentiality of shared model parameters can be ensured through the distributed key generation and homomorphic encryption computing technology, and inference attack threats based on model parameter analysis are avoided. According to the invention, the defect of data privacy in an existing traffic flow prediction system can be overcome, and an effective support technology is provided for intelligent traffic management.

Method and system for generating digital signature following one or more secure protocols based on a threshold additively homomorphic encryption (TAHE) over a broadcast channel, where a threshold of parties of a decentralized network produces digital signature by following a Universally Composable secure protocol configured to output Elliptic curve digital signature algorithm (ECDSA) signature or a Schnorr signature. At least one client may cooperate with the threshold of parties to generate digital signature, or threshold of parties may cooperate to generate digital signature without a client. Method may include additively homomorphic encryption (AHE) distributed key generation (DKG), ECDSA / Schnorr DKG, ECDSA / Schnorr presigning, providing ECDSA / Schnorr child keys, ECDSA / Schnorr signing, wallet transfer and / or network reconfiguration.

The invention provides a distributed key generation method and device based on quantum random numbers, a medium and equipment, and belongs to the technical field of quantum security. According to the method, quantum random number generators are configured for nodes of the block chain, and the nodes generate self-certification information by using quantum random numbers provided by the quantum random number generators and broadcast the self-certification information among the nodes; and after the node successfully verifies the received proof information, generating a signature private key, a verification public key and a global public key of the node by using a quantum random number provided by a quantum random number generator. According to the invention, the quantum random number with true randomness is adopted to generate the distributed key, so that the security of the distributed key is improved.

The invention discloses a unified key management method and device for a distributed password service component, and aims to solve the problems of single-point failure, consistency deficiency and insufficient life cycle management and control of existing key management. According to the method, based on a distributed key generation protocol, Shamir secret sharing, PBFT consensus and Lagrange interpolation, key generation, distributed storage, safe distribution and dynamic rotation whole-process management and control are achieved. The device is composed of n nodes including a processor, a memory and a communication and key processing module, and supports encrypted storage, secure communication and consensus collaboration. Security is guaranteed through a threshold mechanism, hash verification and a hash chain technology, availability is improved through SDN optimization and failover, and nodes and parameters can be flexibly adapted and expanded. The method is applied to scenes such as a power grid, gives consideration to safety, availability and compliance, and is suitable for unified key management of distributed system password services.

The invention discloses a relay cross-chain method and system applied to block chain cross-chain, and belongs to the technical field of block chain interoperation. The method comprises the following steps that: in an anonymous committee election stage, a candidate node performs anonymous drawing by using an anonymous verifiable random function combined with a weight and a temporary identity key; in the key generation stage, an asynchronous distributed key generation protocol is adopted, a reliable broadcast protocol is combined, and a threshold signature private key share is generated on the premise that a complete private key does not need to be reconstructed; in a cross-chain consensus stage, a committee member generates a threshold signature share containing an identity bit vector, an aggregation node encrypts the bit vector by using an accountability public key and generates a zero-knowledge proof, and a binding relationship between an identity ciphertext and an aggregation signature is constructed. According to the invention, identity privacy protection of a whole cross-chain verification process is realized, and the problem of key generation deadlock in an asynchronous network environment is solved.

A distributed threshold signature implementation method, comprising: in a distributed key generation phase, each of n participants generating a first random value and a second random value, performing homomorphic encryption thereon and then exchanging same with other participants, and each participant generating a private key share on the basis of the collected first random value and second random value and the sum of secret shares generated by means of a distributed key generation protocol; in a distributed signature offline phase, each of at least t+1 participants executing: updating its own private key share, generating its own third random value and a corresponding third random value public key, and performing broadcasting; and in a distributed signature online stage, each of the at least t+1 participants executing: after the third random value public keys are all collected, calculating the total coordinates of the third random value public keys, and calculating r in a signature share regarding a message on the basis of the total coordinates, and further calculating a component si of the signature share regarding the message on the basis of r, the third random value of said participant and the updated private key share of said participant, so as to obtain the signature share.

The invention discloses a multi-authority personal data access control method and system based on a block chain, and relates to the technical field of information security, and the method comprises the steps: selecting a large prime number, defining an elliptic curve, constructing a finite field, and generating a master key and an attribute key; submitting a registration application, generating verification parameters by using random numbers and hash, and distributing keys according to user attributes; the AES is adopted to encrypt data, and an access strategy is set by using an attribute encryption key; and extracting block chain key information, and requesting the CCC to output decryption parameters in combination with own attributes. According to the method, multi-authoritative distributed key generation is adopted, and data fine-grained access control is realized in combination with attribute-based and AES (Advanced Encryption Standard) encryption. Through cooperative storage of the IPFS and the block chain, data integrity and non-tampering are ensured; the cloud computing center undertakes partial decryption computing, reduces the load of the terminal, and guarantees the security of the key.

A method for implementing distributed key generation in a blockchain by a blockchain node includes: generating n secret shares, retaining a share and respectively encrypting a remaining n−1 secret shares by using keys of receivers, generating a public verification parameter corresponding to a secret share of the blockchain node, generating a zero-knowledge proof indicating that the secret share of the blockchain node and the public verification parameter match, sending the secret share, the public verification parameter, and the zero-knowledge proof to an on-chain contract by using a transaction, verifying, by the on-chain contract based on the zero-knowledge proof, that the encrypted secret share and the public verification parameter match, obtaining, from contract information, a verified secret share corresponding to the blockchain node, performing decryption by using a key of the blockchain node, and calculating a private key share of the blockchain node based on a local secret share.

The present invention discloses an SM2 threshold signature system based on dynamic secret sharing, which relates to the field of information security technology. The system includes: an initialization module, a distributed key generation module, a signature module and a verification module; the initialization module is used to initialize public parameters; the distributed key generation module is connected to the initialization module, and is used to generate a secret share based on the initialized public parameters; the signature module is connected to the distributed key generation module, and is used to generate a signature pair based on the public parameters and the secret share; the verification module is connected to the signature module, and is used to verify the signature pair. In view of the fact that the existing SM2 threshold signature algorithm cannot use the original signature private key to ensure that the external signature public key remains unchanged when the number of participating users needs to change or the threshold value changes, the present invention uses a distributed key generation module to generate a secret share, which can dynamically add or delete the threshold value and the number of participating users under the premise of ensuring that the original signature private key remains unchanged.

Systems and methods for distributed key generation is provided. In some embodiments, a public key and a private key are generated using elliptical curve cryptography (ECC) at a group of trusted parties. In some cases, an elliptical curve digital signature algorithm may be employed. Each party also generates a commitment and a blinding factor. The blinding factor may be a randomized polynomial integer. The parties use the commitments from the other parties to validate the public keys before receipt and combining the public keys into a group / aggregate public key. Content encryption keys (CEK) are then encrypted at each of the trusted parties using these aggregate public keys to generate wrapped content encryption keys (WCEK). Private keys are sharded and a sharded private key is generated at each party using the pieces of shards received by the trusted party. Subsequently, criteria may be received that allows for the release of these sharded private keys back to a trusted environment / enclave.

The present application belongs to the technical field of information security, and particularly relates to a BLS traceable security threshold signature method and system based on distributed key generation. The method comprises the following steps: S1, generating a bilinear pairing environment, and initializing public security parameters; S2, determining a group mapping relationship based on a symmetric balanced incomplete block design, each participant interacting in a group to generate respective key shares and a system global public key; S3, a signer performing partial signature and zero-knowledge proof corresponding to the partial signature on a message according to the corresponding key share; S4, an aggregator collecting and verifying the partial signature, screening out an effective signature set, aggregating to generate a final signature, and generating a commitment ciphertext; S5, a verifier verifying the final signature, and confirming the signature as valid if the verification is passed; S6, when the verification is not passed, a tracing mechanism is activated, and a tracer traces the signature group; and S7, according to the group mapping relationship, regularly performing active refreshing of the key shares.

The present invention belongs to the field of blockchain technology, and provides a distributed oracle implementation method and system based on threshold signature. The method is applied to the oracle network, including: receiving a request event sent by the blockchain to establish a TLS connection with a specified external data source; according to the request event, the nodes with private key shares use their own private key shares to sign to obtain their own signature shares, and broadcast; if the number of signature shares received by any node in the oracle network exceeds the threshold value t, a complete signature is constructed and sent to the blockchain; so that the blockchain uses the public key to verify the complete signature, and obtains the callback function specified by the user contract according to the request identifier, and executes the result of the callback function and returns it to the user contract; wherein, the private key share and public key are: the distributed key generation protocol is used to generate the private key share and public key for each node. The present invention will not restore the complete key during the signing process.

The invention discloses an MPC threshold signature method and system suitable for HSM, and relates to the technical field of information security and cryptography, and the method comprises the steps: a management module manages a plurality of hardware security modules HSM, coordinates a key generation module of each HSM to execute a distributed key generation protocol DKG, and enables a private key fragment to be directly generated in each HSM and to be encrypted and stored; the MPC threshold signature module receives a to-be-signed message of an application APP and user certificate information, calls the management module to perform identity verification on the user certificate information, and obtains a target HSM node list associated with a user passing verification; the MPC threshold signature module schedules a threshold signature module with at least a threshold value of t HSM nodes according to the target HSM node list, and MPC threshold signature operation is executed in each HSM based on private key fragments; and the MPC threshold signature module receives partial signatures returned by each HSM, and aggregates the partial signatures into a standard digital signature for realizing efficient, compliant and single-point fault resistant digital signature operation on the premise of ensuring absolute security of the private key.

The invention discloses a double-path verifiable threshold signature-based block chain right confirmation and responsibility investigation method, which comprises the following steps of: S1, receiving right confirmation data, processing the data to obtain normalized data, and calculating a data abstract of the normalized data; submitting the data abstract and the associated information thereof to a block chain for evidence storage to form a right confirmation request record; s2, in response to the right confirmation request record, selecting a committee member set from candidate nodes based on a preset strategy, and cooperatively generating a global public key and a private key share corresponding to each committee member by the committee member set through a distributed key generation protocol; and S3, each committee member generates a partial signature for the data abstract by using the private key share of the committee member, and generates a verifiable proof for proving the correctness of the calculation process of the partial signature of the committee member at the same time. According to the invention, independent verification and accurate responsibility tracing of individual signature behaviors of committee members can be realized.

Embodiments of the invention relate to a computer-implemented method for generating verification keys of a public-key signature scheme in a distributed network. The method comprises performing, by a subset of the nodes of a first subnetwork of nodes, a first distributed key generation protocol, the first distributed key generation protocol being configured to generate jointly a verification key for the first subnetwork and a plurality of corresponding secret key shares for the nodes of the first subnetwork. The method further comprises a step of performing, for a second subnetwork, by a subset of the plurality of nodes of the first subnetwork, a second distributed key generation protocol, the second distributed key generation protocol being configured to generate jointly a verification key of the second subnetwork and a plurality of corresponding secret key shares for the nodes of the second subnetwork. A further step comprises signing, by a subset of the nodes of the first subnetwork, the verification key of the second subnetwork with a permissible subset of the secret key shares of the nodes of the first subnetwork, thereby generating a joint signature on the verification key of the second subnetwork.Further aspects relate to a distributed network, a node of a distributed network and corresponding computer program products.

The invention discloses an asynchronous distributed key generation method and device. The method comprises a sharing stage, a negotiation stage, a random extraction stage and a key derivation stage which are executed in sequence. In the sharing stage, an asynchronous complete secret sharing protocol is adopted, and secret share distribution is achieved through the steps of sending, confirmation, preparation and amplification; in the negotiation stage, consensus screening is carried out on terminated secret sharing instances based on a multi-valued verification Byzantine negotiation protocol; in the random extraction stage, a negotiation result is operated by using an ultra-reversible matrix to generate an intermediate parameter; and in the key derivation stage, a key related result is finally output through an online error correction algorithm and Lagrange interpolation calculation. The method gets rid of dependence on public key infrastructure and credible setting, relieves the contradiction between throughput and delay, improves the security, reliability and anti-review performance of the system, and is suitable for a large-scale distributed system or a resource limited environment.

The invention discloses a distributed key generation method, a cross-chain notarization method, a medium and equipment, and the method comprises the steps: obtaining the number of current members of a current committee, a temporary public key and a first constant term when a cross-chain request is received on a block chain, and enabling the members of the committee to change dynamically; based on the current member number, the temporary public key and the first constant term, determining first ciphertext information of the current committee member; determining first coefficient information of the current committee members based on the number of the current members, the first constant term and a specified polynomial function; sending the first ciphertext information and the first coefficient information to a block chain, and obtaining second ciphertext information of other current committee members from the block chain; according to the second ciphertext information and the first coefficient information, the private key fragment and the public key fragment of the current committee member are determined, and no party can grasp the complete key fragment, so that the security of the cross-chain process is improved, and frequent attacks of malicious parties are avoided.