196 results about "Ring signature" patented technology

The invention belongs to the e-commerce technology field and discloses a modifiable reputation evaluation system and method based on a block chain, and an electronic payment system. A receipt from a seller is received by a user, the signature of the seller in the receipt is verified, and the evaluation information is generated; after verification is completed, a ring signature of the evaluation information is generated by the user, and the ring signature is sent to the block chain; the receipt and the ring signature of the user are verified by the block chain; a database is updated after the block is generated; a new signature is acquired by the user through a signature algorithm, and the new signature is sent to the block chain; validity of the signature is verified by the block chain, and whether the two signatures are completed by the same user is determined; a pointer corresponding to the block of a previous message is modified after verification completion, the previous message ismarked as invalid, and the previously-revoked information is replaced by the block of the message. The method is advantaged in that on the condition that user anonymity and transaction non-tamperability are guaranteed, integrity and openness of the evaluation information are guaranteed, and reliability of the evaluation information is guaranteed.

The invention provides a privacy transaction method, a system and a device. The method comprises the following steps: selecting a plurality of available first UTXOs in a privacy address according to atransfer amount; requesting a plurality of second UTXOs with the same quota from a block chain for each of the first UTXOs; selecting a plurality of available first UTXOs in the privacy address according to the transfer amount; and selecting a second UTXO with the same quota from the block chain. Wherein each of the second UTXOs is used for ring signature confusion of UTXOs of transfer transactions; the ring-signed first privacy transaction is sent to a privacy agreement for the privacy agreement to send assets of the same amount as the transfer amount to a recipient account. The ring-signedfirst privacy transaction is sent to a privacy agreement for the privacy agreement to send assets of the same amount as the transfer amount to a recipient account. The device ensures that the sender in the privacy transaction process is not traced through ring signature and confusion technology, and the invention realizes the transaction from UTXO model to account model, so that the block chain system can freely flow in the public account and the privacy account.

The invention provides a blockchain anonymous voting system and method. A voting system is realized by using a block chain; voting logic is put into an intelligent contract for operation; voting datacan be publicized and transparentized; a centralized node does not exist, even if a single node fault occurs, the overall operation of the system is not influenced;, the voting data in the blockchaincan be tampered by any person, and moreover, by introducing cryptographic technologies such as blind signature and ring signature into the blockchain, details such as identity information and voting intention of voters are hidden on the premise of ensuring the openness and legality of necessary voting data, so that the effect of protecting the privacy of users is achieved.

The invention provides a linkablering signature method based on anonymous broadcast encryption, aiming at widening the application range of the linkable ring signature and improving the safety of thelinking verifier.The implementation method comprises following steps: setting ring signature parameters;a ring member IDx gets the public parameter; thering member IDx generates a key and a linkable hash value PKskx. The trusted third party obtains broadcast encryption parameters and calculates broadcast encryption private key SKIDx of ring member IDx. The signer calculates a linkable flag Tag anda flag ciphertext CT and obtains a ring signature sigma of the message m. The verifier verifies the correctness of the ring signature sigma; judging the identity of the verifier; an authorized user verifies the linkability of ring signature sigma; an obtainer calculates the signer information to prove Psi. The verifier verifies the correctness of Psi. The invention can be used for a transaction scene under a block chain which needs permission to judge whether the transaction scene can be linked or not.

The invention provides an Internet of Vehicles privacy protection trust model based on a block chain. Vehicles on the road generate and broadcast messages through the vehicle-mounted ad hoc network toshare surrounding traffic information so as to improve the traffic efficiency and safety. However, due to the untrusted network environment of the vehicle-mounted ad hoc network, the privacy of the vehicle is easy to expose, and whether the received message is reliable cannot be judged. The message is anonymously sent by the vehicle through the ring signature technology, so that the vehicle is prevented from being tracked by a malicious vehicle. Messages sent by the vehicle are evaluated and screened through a reputation evaluation mechanism based on the block chain technology, and forged information in the messages is filtered. Based on the characteristics of the block chain, it is guaranteed that the vehicle reputation is not maliciously tampered, real-time synchronous updating of the vehicle reputation is achieved, and the safety and usability of the vehicle-mounted ad hoc network are further improved.

The invention discloses a ring signature method for anonymizing information based on multivariate public key cryptography, comprising the following steps: generating system parameters, generating a secret key, generating the ring signature and verifying the ring signature. The ring signature method based on the traditional cryptosystem is subjected to security threat under the quantum computer while the ring signature method based on the multivariate public key cryptosystem solves the problem that the existing ring signature systems are insecure under the quantum computation. The method has the advantages of security and high computing efficiency.

The invention provides a privacy transaction method and a system, a device and a storage medium. The method comprises: selecting a plurality of available first UTXOs in a privacy address according toa transfer amount, and requesting a plurality of second UTXOs from a block chain; selecting a plurality of available first UTXOs in the privacy address according to the transfer amount; acquiring a first public key pair of a receiver, generating a first random number, generating a second random number according to the first random number, and generating a one-time public key according to the firstrandom number; taking the one-time public key as the output destination public key of the privacy transaction, taking the second random number as the output information of the privacy transaction, and packaging a plurality of privacy transactions; each of the privacy transactions being sent to a block chain network for consensus through a plurality of ring signatures. The invention ensures the related information of the sender and the receiver by using the ring signature technology and the one-time target address, thereby realizing the unconnectedness and untraceability of the transaction.

A lattice-based ring signature method includes generating a dimension, a bound, a length of a hashed message, a Gaussian parameter and an open parameter, which are parameters necessary for a ring signature. Further, the lattice-based ring signature method includes generating a signature key and a verifying key for a user who construct a ring by using the parameter necessary for the ring signature. Furthermore, the lattice-based ring signature method generating a signature for a message and the ring by using the signature key and the verifying key.

The invention relates to a linkable ring signature method based on an appointed verifier. In the method, a non-interactive zero-knowledge proof technology is adopted, and a linkable ring signature based on the appointed verifier is realized under the hypothesis of the difficulty in a bilinear Diffie-Hellamn problem. According to the invention, the problems that no linkable ring signature method based on the appointed verifier is available in the prior art and the linkable ring signature cannot be used to solve the problem of receipt-freeness in electronic-cash and electronic voting are solved.

The invention discloses a blockchain-based anonymous information transmission method and device, and a readable storage medium. The method comprises the following steps: receiving, by a client, information distributed by a blockchain mechanism, a first public key list and a ring signature parameter required for generating a ring signature, and obtaining information to be transmitted correspondingto the information distributed by the mechanism according to the operation of a user of the client; performing ring signature on the information to be transmitted by using the ring signature parameter, other user pubic keys in the first public key list and a private key corresponding to the public key of the client to obtain an information signature; and sending the information to be transmitted and the information signature to the mechanism, so that the mechanism, receives the information to be transmitted and the information signature and uploads the information to be transmitted and the information signature to a blockchain after determining that the information signature is in an effective state. By adoption of the blockchain-based anonymous information transmission method and device disclosed by the invention, the anonymous information transmission is realized; and by writing the information to be transmitted and the corresponding information signature into the blockchain, the non-tampering of the information to be transmitted is achieved by the characteristics of the blockchain.

According to some embodiments of the invention, a message is processed before encryption so that the encryption method generates a short ciphertext. The message processing can be viewed as a mapping (610) that maps the message into another message that generates the short ciphertext. The mapping is reversible at least if the (possibly encoded) message (H(M)) is in a restricted set, e.g. a set [0,h?] of short messages. In some embodiments of the present invention, short signatures are provided by mapping the signature into a short signature. The mapping (810) is reversible at least if the original message (H(M)) used to generate the signature is short. Signcryption, aggregate signature, and ring signature outputs are also shortened.

An anti-adaptive attack alliance chain consensus method based on Byzantine fault tolerance comprises the following steps: constructing an anonymous sorting master selection algorithm based on ring signatures, and selecting a potential proposor PP from all consensus nodes in an alliance chain network in a concealed manner; enabling a potential proposor PP to construct a proposal block, sign the proposal block and broadcast the proposal block to the alliance chain network; enabling the consensus node to verify the received proposal block, vote the proposal block passing the verification based on a threshold signature, and broadcast a voting result in the alliance chain network; if a consensus node receives a legal threshold signature of the proposal block within a predetermined time, enabling the proposal block to complete the consensus; and enabling all nodes in the alliance chain network to store the blocks completing the consensus. The method has the advantages that the system overhead is reduced, the expandability is improved, the safety is higher, the system activity can be effectively ensured before and after proposal, and the support is provided for a high-availability Byzantine system.

The invention relates to the technical field of network security, and provides a vehicle-mounted-network anonymous-communication system based on ring signature. The system includes a third-party trustinstitution, road side units and vehicles. The invention also provides a method of using the above system for vehicle-mounted-network anonymous-communication. The third-party trust institution firstly publishes public parameters, then the vehicles and the road side units apply for registration to the third-party trust institution, the third-party trust institution issues pseudonyms and public andprivate keys for the vehicles, and issues public and private keys and initial pseudonym ring members for the road side units, and then states of the vehicles in a vehicle-mounted network are monitored; and initial accessing authentication is carried out with a road side unit RSU if a vehicle accesses the vehicle-mounted network for the first time, and switching accessing authentication is carriedout with a road side unit RSU' if the vehicle does out access the vehicle-mounted network for the first time, and two-way authentication is carried out under assistance of a road side unit if a vehicle Vi is ready to communicate with a vehicle Vj. The system and the method integrate pseudonym certificate and group signature technology, and can fully protect privacy safety of communicators on thepremise of ensuring authentication efficiency.

The invention provides a trusted LBS service protocol implementation method based on privacy protection, and belongs to the technical field of Internet of Vehicles security. According to the technicalscheme, the trusted LBS protocol implementation method based on privacy protection comprises the four steps of system setting, user registration, position hiding and signature verification. The beneficial effects of the invention are as follows: bidirectional trusted communication between a vehicle user and an LBS server in an Internet of Vehicles LBS environment is realized, position concealmentand identity concealment are generated through cooperation of an OBU, the LBS and the TA, position concealment of the LBS server by the OBU is achieved, meanwhile, identity authentication of the OBUis achieved, and the adopted certificateless ring signature scheme is more suitable for the Internet of Vehicles environment and has unconditional anonymity and unforgeability.

A system, method, apparatus, and computer program product for a privacy ensured brokered identity federation system. The privacy ensured brokered identity federation system connects a user in a brokered identity federation environment that blinds relying parties (RP) from credential service providers (CSP), blinds CSPs from RPs, and blinds a user's identity and data from the federation middleware hubs. The system utilizes ring signatures to attest to CSPs that a valid RP of the federation is making a request. The process utilizes CSP ring signatures to assure RPs that a valid CSP of the federation has provided a response. The process utilizes per transaction encryption keys created by the RP to ensure the federation has no access to data messages. It can further ensure that only the correct RP can decrypt a CSP response.

The invention relates to a location privacy based ring signature method in the Internet of vehicles, belongs to the field of vehicle identity authentication in the Internet of vehicles, and aims at solving the problem in detecting collusive Sybil attacks. Path information of a vehicle is used as identity information of the vehicle, the path information contains location privacy information of the vehicle, and location privacy information is protected in the ring signature method. Compared with a present Sybil attack detection method, the vehicle identity authentication method provided by the invention can make vehicles independent from each other, protect the location privacy of the vehicles, and detect the novel collusive Sybil attack existing in the Internet of vehicles in real time.

The invention discloses an editable, linkable and non-repudiation ring signature method, belongs to the field of network security, and solves the problems of difficulty in revocation of a ring signature, difficulty in tracing identity information of a malicious user, capability of being authenticated by the signature after being edited, no privacy protection, no flexible authentication mechanism and the like in the prior art. The method is used for sequentially carrying out system initialization, user key generation, hash key generation and signature and providing conditional revocation identity privacy, editable and non-repudiation ring signatures. After the signature is edited, if the signature is required to be edited and whether the signature can be linked or repudiated is judged, thesignature is verified respectively, and after the verification is passed, the signature is edited and whether the signature can be linked or repudiated and the like is judged to be used for providingidentity privacy capable of being revoked, editable and non-repudiated ring signatures.

An identity-based threshold ring signature method comprises the following steps: (1), system establishment; (2), private key extraction; (3), signature; and (4), verification. The method provided by the invention is established under a standard model and has better security compared with a scheme designed under a random predictive model.

The invention discloses a ring signature method for anonymizing information based on multivariate polynomial, comprising the following steps: generating system parameters, generating a secret key, generating the ring signature and verifying the ring signature. The ring signature method based on the traditional cryptosystem is subjected to security threat under the quantum computer while the ring signature method based on the multivariate public key cryptosystem solves the problem that the existing ring signature systems are insecure under the quantum computation. The method has the advantagesof security and high computing efficiency.