43 results about "Private information retrieval" 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 provides a homomorphic keyword privacy information retrieval method and system based on polynomial linking.The homomorphic keyword privacy information retrieval method and system based on polynomial linking.The homomorphic keyword privacy information retrieval method comprises the steps that data items in a database are segmented; the method comprises the following steps: processing keywords in a database by using cuckoo Hash, and publishing a used Hash function; creating a zero-value polynomial by using the processed elements in the table, and creating an interpolation polynomial on the segmented data items by using a polynomial linking technology and taking a hash value as a root; respectively calculating hash values of keywords expected to be queried by utilizing the published hash function; the method comprises the following steps: encrypting a hash value of a keyword expected to be queried by using a fully homomorphic encryption technology, and respectively calculating a value of each polynomial; and decrypting the value of the first zero-value polynomial, if 0 exists, indicating that the keyword is matched with the query, decrypting the value of the interpolation polynomial, and outputting a result obtained by the query. According to the method, the practicability of private information retrieval is expanded.

The invention discloses a verifiable privacy information retrieval mechanism based on homomorphic encryption. The method comprises the following steps: S1, after initialization is completed, a data owner generates a zero-knowledge proof while constructing a private information retrieval challenge, proves that a challenge structure is legal, and submits the proof to a trusted third party (TTP); s2, the server receives the inquiry verified by the TTP and then performs homomorphic calculation, generates an encrypted response and sends the result to the data owner and the TTP, and the TTP synchronously records response information; s3, the data owner carries out decryption and Hash comparison on a returned result, if an exception is found, an objection request can be submitted, and verification is carried out by the TTP in combination with challenge and response zero-knowledge proof; and S4, arbitration and responsibility tracing: the TTP judges the dispute based on a verification result, and determines a responsibility party. The method is suitable for private information retrieval scenes with high requirements on data security and integrity.

The invention relates to the technical field of privacy information retrieval, in particular to a privacy information retrieval method supporting a Boolean retrieval model and related products, and the method comprises the steps of database remodeling, coding and encryption, homomorphic operation, logical operation processing, result calculation and decryption output. According to the method, by introducing constant weight coding and a privacy protection mechanism based on homomorphic encryption, the privacy of user retrieval content is ensured, and meanwhile, complex Boolean logic operation is supported, so that the expressive force and accuracy of information retrieval are improved. Through structural remodeling of a keyword-value database, the method realizes efficient processing of many-to-many relational data, and reduces the overhead of calculation and communication; due to the introduction of the logical operation processing module, a user can realize complex retrieval conditions through combination of Boolean operators such as AND, OR and NOT, and specific retrieval information does not need to be leaked.

The invention provides a symmetric private information retrieval method and device, a medium, a program product and a system. According to the method, the limitation that the number D of databases of an information source is equal to 1 is broken through, and the retrieval frequency Q of an information sink is equal to D or 1lt; qlt; according to the method, information retrieval is realized under D, an inadvertent key distribution and post-processing method is not increased according to the number D of the databases and the retrieval times Q, that is, one inadvertent key distribution is matched with one post-processing method to help an information sink to complete Q times of information retrieval from the D databases, and collapse processing also improves the security in data transmission. Therefore, the problems that the communication complexity between the information source and the information sink is increased and the retrieval efficiency is influenced due to the careless key distribution of the symmetric private information retrieval method in the existing scheme are solved.

This invention provides a dynamic update method for single-server preprocessing of Private Information Retrieval (PIR), including an offline preprocessing stage, a dynamic database update stage, an online query stage, and an update stage. Based on the existing single-server preprocessing PIR retrieval scheme Piano, this invention adds support for dynamic database operations, supporting CRUD (Create, Read, Update) operations on the database. Unlike the cumbersome preprocessing work of comparable schemes, this invention introduces incremental preprocessing technology, allowing the original preprocessing to continue to be used after database changes, while incurring update costs proportional to the number of changes, rather than proportional to the size of the database. Compared to existing technologies, this invention reduces total communication costs, client computation time, and client storage space.

The invention relates to the technical field of information encryption and decryption, can be applied to business scenes such as financial science and technology and medical health, and discloses a filter matrix keyword retrieval method, device and equipment and a medium. Receiving a query keyword and generating a hash position set, constructing an index vector and generating an encrypted query vector and query state information, executing homomorphic inner product processing by the server based on the filter matrix and the encrypted query vector to generate encrypted response data, and reconstructing and generating a query result based on the query state information. According to the method, encryption query and result reconstruction are achieved through the binary fusion filter and the homomorphic inner product mechanism, query content leakage is avoided, calculation and communication overhead is reduced through matrix processing, the keyword retrieval function is kept, meanwhile, the efficiency is close to index type PIR, and the private information retrieval practicability is improved.

The invention provides a multi-keyword private information retrieval method and system based on inverted indexes, and belongs to the field of information security and privacy computing. The method comprises the following steps that: a server splits an original database into a reverse index part of a keyword-index set and a key value pair part of an index-data value; mapping the index set into an integer by utilizing Godel coding; processing the data by adopting probability batch coding and binary random linear coding and publishing a hash function; the client maps a multi-keyword query into a bucket by using a hash function to generate a query vector, and the query vector is sent to the server after being subjected to fully homomorphic encryption; the server performs homomorphic calculation on a matching result in a ciphertext state and returns the result; and the client obtains a matching index set after decryption verification, and then initiates a second round of query to obtain final data. According to the method, symmetric privacy protection of multi-keyword non-primary key query in a single-server environment is realized, leakage of query content and database information is effectively prevented, and private information retrieval security is improved.

The invention discloses a dynamic single-server client preprocessing private information retrieval method, and belongs to the technical field of private information retrieval. The method comprises a preprocessing stage: a client generates a private prompt and stores the private prompt in a local device; a query and response stage: the client accelerates query by using a private prompt; in the refreshing stage, the client repositions the used private prompt and updates the private prompt stored locally; and a dynamic updating stage: when the server updates or deletes the original data item or adds a new data item, the client directly updates the private prompt stored locally. According to the method, the client storage time and the server online calculation time are optimally balanced, and meanwhile, efficient updating of the dynamic database is supported. And when the database of the server dynamically changes, the private prompt stored in the local equipment of the client can be updated within the expected PRP calling time, so that the private prompt updating efficiency in a dynamic database scene is remarkably improved.

Described systems and methods allow carrying out privacy-preserving DNS exchanges. In some embodiments, a client machine engages in a private information retrieval (PIR) exchange with a nameserver. In response to receiving an encrypted query from the client, the query formulated according to a domain name, the nameserver may extract a record (e.g., an IP address) from a domain name database without decrypting the respective query. Some embodiments achieve such information retrieval by the use of homomorphic encryption.

Parameter permutation is performed for federated learning to train a machine learning model. Parameter permutation is performed by client systems of a federated machine learning system on updated parameters of a machine learning model that have been updated as part of training using local training data. An intra-model shuffling technique is performed at the client systems according to a shuffling pattern. Then, the encoded parameters are provided to an aggregation server using Private Information Retrieval (PIR) queries generated according to the shuffling pattern.

The invention relates to the technical field of information security, in particular to a high-throughput privacy information retrieval method suitable for a dynamic database. Comprising the following steps: S1, server preprocessing: inputting a security parameter, a public seed and a database, and outputting an offline prompt comprising a first dimension of the database; s2, the client generates query information: inputting a security parameter, a public seed and an index (i, j) to be queried, and outputting query information qu and a private key sk; s3, service device online response query: inputting a database, query information qu and an offline prompt, and outputting response information; and S4, the client decrypts the response information: inputting the private key sk and the response information, and outputting a data item including retrieval. According to the method and the device, the throughput is further improved, the demand for offline prompt downloading of the client is eliminated, the server is ensured to only return information required by the user, the time of private information retrieval is greatly shortened, and the user experience and the data retrieval efficiency are remarkably improved.

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.

This application proposes a verifiable private information retrieval method against RAG knowledge base poisoning attacks, comprising the following steps: The server maps each data fragment in the knowledge base to a polynomial form in a polynomial ring to obtain the server-side knowledge base; the client generates a query polynomial and a private key based on the polynomial ring, generates a private commitment based on the private key, constructs a private query, and sends it to the server; the server performs ciphertext field retrieval calculation on the polynomial ring based on the private query to generate a ciphertext polynomial for the retrieval response; the client performs decryption operation on the ciphertext polynomial for the retrieval response in the response message using the private key to obtain the retrieval result. This scheme generates a unique version identifier and knowledge base commitment for the server-side knowledge base. When the knowledge base content is legally updated, a new knowledge base commitment and version identifier are generated and published simultaneously, without the need to reconstruct the entire knowledge base index, significantly reducing the preprocessing overhead and time cost of dynamic updates to the knowledge base in private retrieval.

The invention relates to the technical field of privacy protection, in particular to a privacy information retrieval method and device based on differential privacy, and the method comprises the steps: obtaining at least one piece of key information of a user, and generating a plurality of indexes in a data retrieval server according to the at least one piece of key information; searching a local group corresponding to each index in a data processing server; traversing the XOR result in the group corresponding to each index, and determining a target value corresponding to each index according to the XOR result; summing the target value corresponding to each index to obtain a summing result, and adding target Laplacian noise to the summing result to generate a final query result. Therefore, the problems that when a group of user data is queried by an existing privacy protection technology, certain hidden dangers in the aspect of data security can occur, and the risk of user information leakage occurs are solved.

The application discloses a kind of private information retrieval method, equipment, storage medium and program product of supervision, it is related to cryptography and privacy computing technical field.The method comprises: by data holder, public verifiable cryptography commitment is completed in system initialization phase to database version, and database version commitment is recorded to evidence chain by supervision committee, and threshold signature system is established;By supervision committee, the compliance audit is carried out to external authorization certificate and authorization message provided by inquirer, threshold signature is generated when audit passes, and authorization event is recorded to evidence chain;By inquirer, authorization query package is assembled based on threshold signature and is submitted to data holder;In the case where data holder is verified to threshold signature and authorization query package and confirms that authorization is legal and is consistent with database version commitment binding, response ciphertext is generated.The application realizes the authorization decision and after-the-fact accountability of encrypted query, reduces the trust assumption to single-point approval subject.

The present invention relates to the field of information security technology, and more specifically, to a method for retrieving private information based on homomorphic encryption. The method comprises the following steps: S1. Server preprocessing; S2. Client generating query information; S3. Server responding to the query online; S4. Client decrypting the response information; and S5. Server updating the database. The present invention provides a method for retrieving private information based on homomorphic encryption. Client query requests can be responded to within a sublinear time complexity, significantly reducing the time complexity of previous private information retrieval processes and helping to improve user experience and data retrieval efficiency. Furthermore, the technology provides strong privacy protection, ensuring that users' personal information and sensitive data are fully protected.

The application discloses a dynamic single-server client preprocessing private information retrieval method, and belongs to the technical field of private information retrieval. The method comprises a preprocessing stage: a client generates a private hint and stores the private hint in a local device; a query and response stage: the client uses the private hint to accelerate query; a refreshing stage: the client repositions the used private hint and updates the locally stored private hint; and a dynamic updating stage: when the server updates or deletes original data items or adds new data items, the client directly updates the locally stored private hint. The application realizes the best trade-off between the client storage and the server online calculation time, and supports efficient updating of a dynamic database. When the database of the server dynamically changes, the private hint stored in the local device of the client can be updated within the expected PRP calling time, and the updating efficiency of the private hint in a dynamic database scenario is remarkably improved.

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 application belongs to the technical field of privacy protection, and provides a DID-based authorized private information retrieval method, which comprises the following steps: a receiver and a possessor register to generate a DID and a DID document and upload them to a blockchain; the possessor encrypts a file through a symmetric key to obtain ciphertext and uploads the ciphertext to a database server; the receiver sends file information to the possessor; the possessor signs file attribute information of the corresponding file to obtain a signature value, encapsulates the signature value and the DID of the possessor into a verifiable credential, and sends the verifiable credential to the receiver; the receiver analyzes the verifiable credential to obtain the signature value, and then performs an OSBE protocol on the signature value among the receiver, the database server and the possessor; the receiver obtains the symmetric key, the database server sends the ciphertext to the receiver, and the receiver decrypts the ciphertext through the symmetric key to obtain the file. The application not only meets the query privacy requirement, but also provides a data retrieval scheme in which access control and data subject authorization mechanism are unified.

This application proposes a keyword private information retrieval method and device based on a hierarchical dynamic constant weight code, including the following steps: constructing a multidimensional hypercube storage unit and a collision-resistant hash function through the server, mapping the coordinates of each data in the hypercube storage unit to a unique coordinate constant weight code in a hierarchical mapping manner; the client obtains a query vector and sends it to the server; the server expands the query vector to obtain an extended query vector, obtains the query result based on the extended query vector, and returns the query result to the client; the client decrypts the result and obtains the data to be retrieved based on the key-value pair. This solution uses a multidimensional hypercube storage unit and a collision-resistant hash function to perform data mapping and storage, reducing hash conflicts and avoiding global reconstruction, and optimizes the index update time complexity through hierarchical dynamic constant weight codes to achieve dynamic incremental expansion.

The application relates to the technical field of anonymous communication and provides an anonymous communication method and system based on blind signature and a medium, the method comprising the following steps: a sender generates a blind signature request containing public metadata and a message token, sends the blind signature request to a signature server, and the signature server performs blind signature; the sender performs de-blinding on the received blind signature result, obtains an anonymous token, and sends an authorization request to a bulletin board server; the bulletin board server verifies the validity of the anonymous token, allocates a mailbox and a corresponding writing time window to the sender; the sender obtains the writing permission of the mailbox within the time window, and then delivers a ciphertext to the mailbox; a receiver sends a private information retrieval request to the bulletin board server based on the mailbox identifier informed by the sender, and receives returned response ciphertext; and the receiver uses a PIR private key and a session key to decrypt the response ciphertext, and obtains a plaintext message. The application guarantees the strong privacy of both communication parties and realizes the safe transmission of confidential messages.

The invention belongs to the technical field of privacy protection, and provides a DID-based authorizable private information retrieval method, which comprises the following steps: a receiver and an owning party register to generate a DID and a DID document and upload the DID and the DID document to a block chain, the owning party encrypts the document through a symmetric key to obtain a ciphertext and uploads the ciphertext to a database server, the receiver sends the file information to the owning party, and the owning party sends the file information to the database server. The owner signs the file attribute information of the corresponding file to obtain a signature value, packages the signature value and the DID of the owner into a verifiable voucher, sends the verifiable voucher to the receiver, analyzes the verifiable voucher to obtain a signature value, then executes an OSBE protocol on the signature value among the receiver, the database server and the owner, the receiver obtains a symmetric key, and sends the symmetric key to the database server. And the database server sends the ciphertext to a receiver, and the receiver decrypts the ciphertext through the symmetric key to obtain the file. According to the method, the query privacy requirement is met, and a data retrieval scheme in which access control and a data subject authorization mechanism are unified is provided.

The invention discloses a large-model fine-tuning intelligent disaster recovery big data early warning analysis method and system, and the method comprises the steps: obtaining disaster index data from each distributed data center, carrying out the clustering cleaning of the data through a clustering algorithm, and forming a standardized clustering data set; mapping the data of different disaster levels into computing power tasks, and quantifying the computing power demand of each task in combination with a computing power efficiency value; performing three-stage fine tuning on the basic large model based on the standardized data set and the computing power efficiency value, wherein the three-stage fine tuning comprises ridge regression preliminary training, difficult point data intensified training and special small model generation, and joint fine tuning according to disaster grades; and a longitudinal joint prediction algorithm is adopted, homomorphic encryption and private information retrieval technologies are combined, and the occurrence probability of each disaster grade and a final early warning result are output. The system comprises a data preprocessing module, a calculation power conversion module, a large model fine tuning module and a joint prediction and early warning module. According to the invention, the accuracy, real-time performance and privacy protection capability of disaster recovery early warning are improved.

A system for performing private information retrieval may include a data requesting computer that is configured to receive a query string, homomorphically encrypt the query string to generate an encrypted query, transmit the encrypted query to a data repository computer, and receive resultant encrypted datasets. The data repository computer may be configured to access a database comprising a plurality of datasets, receive the encrypted query, and perform a search of the plurality of datasets to identify the resultant encrypted datasets that include data that matches the encrypted query for provision to the data requesting computer. The search may be performed such that encryption of the encrypted query is maintained while performing computational operations of the search.

The present application belongs to the technical field of password leakage detection, and provides a password leakage detection method and system based on private information retrieval, which performs password leakage service detection, obtains a username-password pair, encodes the username-password pair, interacts with a server, obtains an unintentional key-value storage data structure stored by the server, decodes the encoded username-password pair by using the unintentional key-value storage data structure, obtains a specific location index of a data bucket in which the username-password pair exists, performs private information retrieval between the unintentional key-value storage data structure and the server, obtains a data set in which the username-password pair to be detected exists, searches the obtained data set for whether there is an encoded value matching the encoded value of the username-password pair to be detected, and respectively prompts according to the result. The present application can solve the problems of low efficiency, insufficient security, and insufficient integration effect of existing password leakage detection, and improve the efficiency of password leakage detection.

The invention provides a keyword private information retrieval method and device based on a hierarchical dynamic constant weight code, and the method comprises the following steps: constructing a multi-dimensional hypercube storage unit and an anti-collision hash function through a server, and mapping the coordinate of each data in the hypercube storage unit into a unique coordinate constant weight code in a hierarchical mapping manner; the client obtains a query vector and sends the query vector to the server; the server expands the query vector to obtain an expanded query vector, obtains a query result based on the expanded query vector, and returns the query result to the client; and the client decrypts the result and obtains the to-be-retrieved data according to the key value pair. According to the scheme, data mapping storage is carried out through the multi-dimensional hypercube storage unit and the anti-collision hash function, hash conflicts are reduced, global reconstruction is avoided, index updating time complexity is optimized through layered dynamic constant weight codes, and dynamic incremental expansion is achieved.

A method and system for batch private information retrieval that resists Byzantine attacks, the method comprising: a client receiving a prompt for verification generated by masked data of an original file; the client constructing a query based on an index set of a batch query; calculating and generating a response corresponding to the query; the client verifying the response based on the prompt, and if the response verification passes, obtaining the retrieved file set; if the response verification fails, initiating a challenge for response verification; the client performing response verification, and if the response verification passes, obtaining the retrieved file set; if the response verification fails, terminating the protocol. The present invention can identify Byzantine servers and implement batch retrieval, and can obtain correct results when there is only one honest server, thereby protecting the user's query privacy and the correctness of the retrieval results, and improving query efficiency. The client of the present invention has low storage overhead, and as the number of files continues to increase, the amount of data required to be stored by the client increases less.

The present invention provides a privacy information retrieval method based on NTRU homomorphic outer product. First, the database is regarded as a v+1-dimensional hypercube. The user User generates the corresponding query tuple (i, j1, j2, ..., j) from the query index idx. v ), compress and encrypt the query tuple to obtain a RLWE ciphertext c as the query query , the ciphertext c query Send it to the server, and the server will query the c based on the ciphertext extension algorithm. query Expanded to v+1 groups of ciphertext CT Ntru , CT NtruGSW，0 , CT NtruGSW，1 ,…,CT NtruGSW，v‑1 , and according to the database hypercube form, use NTRU homomorphic outer product calculation to generate the ciphertext response result c respond , sent to the user User, who uses the NTRU decryption algorithm to recover the result d idx The solution of the present invention realizes the hidden query of database data records, reduces the complexity of the ciphertext query vector expansion algorithm, and improves the throughput and query calculation efficiency of private information retrieval.

Parameter permutation is performed for federated learning to train a machine learning model. Parameter permutation is performed by client systems of a federated machine learning system on updated parameters of a machine learning model that have been updated as part of training using local training data. An intra-model shuffling technique is performed at the client systems according to a shuffling pattern. Then, the encoded parameters are provided to an aggregation server using Private Information Retrieval (PIR) queries generated according to the shuffling pattern.