A privacy preserving data sharing method and system

Abstract

The application relates to the technical field of data processing, and discloses a privacy protection data sharing method and system. The method comprises the following steps: performing reversible privacy protection processing on original data to obtain transformed data and restoration mapping information; uploading the transformed data to a data sharing platform after associating the transformed data with a data identifier of a data holding end, and storing the restoration mapping information in a secure execution environment after associating the restoration mapping information with the data identifier; performing identity authentication on a data access request of a data request end to generate a temporary access credential, wherein the temporary access credential contains authorization policy information; submitting the temporary access credential to the secure execution environment to verify the temporary access credential by calling an access control contract in the secure execution environment; extracting a mapping subset corresponding to the authorization policy information from the restoration mapping information; performing an inverse restoration operation on the transformed data to obtain target data, and returning the target data to the data request end; and the application can improve the efficiency of privacy protection data sharing.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and in particular to a privacy-preserving data sharing method and system. Background Technology

[0002] Existing technologies cannot perform segmented reversible privacy protection processing on raw data, are difficult to generate standardized transformed data and restoration mapping information, do not adopt a mechanism for separating and storing transformed data and restoration information, pose a risk of data leakage during sharing and transmission, and have insufficient security control capabilities.

[0003] Existing technologies have significant shortcomings in the data access and restoration process. They lack multi-level authentication and access control contract verification mechanisms, cannot generate temporary access credentials with authorization policies, cannot accurately extract mapping subsets according to permissions and complete data reverse restoration, have low data sharing efficiency, and lack fine-grained permission control, making it difficult to meet the requirements for secure and compliant sharing. Summary of the Invention

[0004] This invention provides a privacy-preserving data sharing method and system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a privacy-preserving data sharing method, comprising: S1: Perform reversible privacy protection processing on the original data of the data holder to obtain the transformed data of the data holder and the corresponding restoration mapping information; S2: After associating the transformed data with the data identifier of the data holder, upload it to the data sharing platform, and after associating the restored mapping information with the data identifier, store it in the secure execution environment; S3: Authenticate the data access request from the data requesting end and generate a temporary access credential for the data requesting end, wherein the temporary access credential contains authorization policy information; S4: Submit the temporary access credential to the secure execution environment and call the access control contract in the secure execution environment to verify the temporary access credential; S5: After successful verification, extract the mapping subset corresponding to the authorization strategy information from the restoration mapping information according to the authorization strategy information; S6: Based on the mapping subset and the data identifier, perform a reverse restoration operation on the transformed data to obtain the target data of the data requesting end, and return the target data to the data requesting end.

[0006] In a preferred embodiment, the reversible privacy protection processing of the original data at the data holding end to obtain the transformed data and corresponding restoration mapping information at the data holding end includes: Perform data block operation on the original data of the data holder to obtain the data block of the data holder, and configure block index identifier for the data block; Based on the data structure characteristics of the data block, a policy mapping is performed on the data block to obtain the reversible transformation policy of the data block; Based on the reversible transformation strategy, the data block is subjected to independent format transformation to obtain the transformed data of the data holding end; Based on the block index identifier and the reversible transformation strategy, construct the restoration mapping information of the data holding end.

[0007] In a preferred embodiment, the step of associating the transformed data with the data identifier of the data holder and uploading it to the data sharing platform includes: The data structure features of the transformed data are subjected to feature mapping to obtain the data fingerprint of the transformed data; The data fingerprint and data identifier are hash-bound together to obtain the associated mapping metadata of the transformed data; The associated mapping metadata is embedded into the metadata section of the transformed data, and together with the data payload section of the transformed data, they are encapsulated into a data object carrying the data identifier; The data object is transmitted to the data sharing platform, and the associated mapping metadata embedded in the data object is parsed in the data sharing platform; Extract the data identifier and the storage address of the data object, and construct an index mapping table entry between the data identifier and the storage address; The index mapping table entry is written into the retrieval directory of the data sharing platform, so that the retrieval directory can locate the data object using the data identifier.

[0008] In a preferred embodiment, the step of associating the restored mapping information with the data identifier and storing it in a secure execution environment includes: The data structure of the restored mapping information is parsed to extract the set of mapping entries in the restored mapping information; Based on the mapping entry set and the data identifier, construct a binding relationship record for the restored mapping information; The binding relationship record is encapsulated into a secure storage object, and the secure storage object is submitted to the secure execution environment; In the secure execution environment, allocate independent storage space for the secure storage object and set access control policies for the independent storage space; The mapping logic of the binding relationship record is written into the access control policy, and an permission anchor point is established between the binding relationship record and the data identifier according to the access control policy; Based on the permission anchor, the restoration mapping information is associated with the data identifier and stored in the secure execution environment.

[0009] In a preferred embodiment, the step of authenticating the data access request from the data requesting end and generating a temporary access credential for the data requesting end, the temporary access credential containing authorization policy information, including: Receive a data access request submitted by a data requester, and extract the identity authentication factor of the data requester from the data access request, wherein the identity authentication factor includes the identity identifier and digital signature of the data requester; The identity authentication factor is submitted to the identity authentication service in the secure execution environment, and the identity authentication service is invoked to perform a signature verification operation on the digital signature to obtain the identity authentication result of the identity authentication factor; When the authentication result is successful, obtain the authorization policy information of the data requesting end; Based on the authentication result and the authorization policy information, construct the main data structure of the temporary access credential; The identity identifier and the authorization policy information are written into the main data structure, and the main data structure is encrypted to obtain the encrypted credential body of the identity authentication factor; The encrypted credential body is combined and encapsulated with the hash value of the identity identifier to obtain the temporary access credential of the data requesting end.

[0010] In a preferred embodiment, submitting the temporary access credential to the secure execution environment and invoking the access control contract in the secure execution environment to verify the temporary access credential includes: Submit the temporary access credentials to the decryption service in the secure execution environment; Based on the decryption service, the temporary access credential is restored and decrypted to obtain the requester's identity, authorization policy information, and credential validity period information of the temporary access credential. The requester's identity, the authorization policy information, and the credential validity period information are transmitted to the access control contract in the secure execution environment. Based on the access control contract, the identity identifier, authorization policy information, and credential validity period information of the requesting party are verified to obtain the verification result of the temporary access credential.

[0011] In a preferred embodiment, after the verification is successful, based on the authorization policy information, a subset of mappings corresponding to the authorization policy information is extracted from the restored mapping information, including: Based on the verification results, extract the scope of the authorization data identifier and the permission level of the data field from the authorization policy information; Extract the complete mapping entry associated with the data identifier from the restored mapping information; Based on the authorized data identifier range, the complete mapping entries are filtered at the first level to obtain the first filtering result of the restored mapping information; Based on the data field permission level, the first filtering result is filtered at a second level to obtain the second filtering result of the restored mapping information; According to the complete mapping entries, the second filtering results are sorted and assembled to obtain the mapping subset of the restored mapping information.

[0012] In a preferred embodiment, the step of performing a reverse restoration operation on the transformed data based on the mapping subset and the data identifier to obtain the target data of the data requesting end, and returning the target data to the data requesting end, includes: Parse the mapping subset and extract the data block index identifier and restoration path information from the mapping subset; Based on the data identifier, locate and obtain the transformation data associated with the data identifier from the data sharing platform, and parse the transformation data block corresponding to the data block index identifier from the transformation data; Based on the restoration path information, the transformed data block is subjected to a reverse transformation operation to obtain the restored data block of the data requesting end; Based on the order of the data block index identifiers, the restored data blocks are spliced ​​and assembled to obtain the target data of the data requesting end; The target data is encapsulated into a response message, and the response message is returned to the data requesting end.

[0013] In a preferred embodiment, the step of performing a reverse transformation operation on the transformed data block based on the restoration path information to obtain the restored data block from the data requesting end includes: The restoration path information is parsed to obtain the transformation mode identifier, transformation parameters, and integrity check value of the restoration path information. Based on the transformation mode identifier, determine the reverse transformation logic of the restoration path information; Based on the transformation parameters, the transformed data block is subjected to inverse transformation processing to obtain the initial restored data block of the data requesting end; The integrity of the initial restored data block is verified using the integrity check value to obtain the restored data block from the data requesting end.

[0014] To address the above problems, the present invention also provides a privacy-protected data sharing system, the system comprising: The data protection module is used to perform reversible privacy protection processing on the original data of the data holder to obtain the transformed data of the data holder and the corresponding restoration mapping information. A separate storage module is used to associate the transformed data with the data identifier of the data holder and upload it to the data sharing platform, and to associate the restored mapping information with the data identifier and store it in a secure execution environment; An authentication module is used to authenticate the data access request from the data requesting end and generate a temporary access credential for the data requesting end, wherein the temporary access credential contains authorization policy information. The credential verification module is used to submit the temporary access credential to the secure execution environment and call the access control contract in the secure execution environment to verify the temporary access credential. The on-demand extraction module is used to extract the mapping subset corresponding to the authorization policy information from the restoration mapping information after the verification is passed, based on the authorization policy information. The data restoration module is used to perform a reverse restoration operation on the transformed data according to the mapping subset and the data identifier to obtain the target data of the data requesting end, and return the target data to the data requesting end.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention generates transformed data and restored mapping information by performing reversible privacy protection processing on the original data. It adopts a separate storage mechanism to deploy the transformed data and restored mapping information on a shared platform and a secure execution environment, respectively, thereby improving the security and controllability of data storage and transmission.

[0016] 2. This invention generates temporary access credentials through multi-level authentication and access control contract verification, accurately extracts mapping subsets based on authorization policies and completes data reverse restoration, realizing on-demand data access and secure restoration, significantly improving the efficiency, accuracy and compliance of privacy-protected data sharing. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a privacy-preserving data sharing method according to an embodiment of the present invention; Figure 2 This is a functional block diagram of a privacy-protected data sharing system provided in an embodiment of the present invention; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] This application provides a privacy-preserving data sharing method. The executing entity of this privacy-preserving data sharing method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the privacy-preserving data sharing method can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster. The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms.

[0020] Reference Figure 1 The diagram shown is a flowchart illustrating a privacy-preserving data sharing method according to an embodiment of the present invention. In this embodiment, the privacy-preserving data sharing method includes: S1: Perform reversible privacy protection processing on the original data of the data holder to obtain the transformed data of the data holder and the corresponding restoration mapping information; In this embodiment of the invention, the reversible privacy protection processing of the original data at the data holding end to obtain the transformed data and corresponding restoration mapping information at the data holding end includes: Perform data block operation on the original data of the data holder to obtain the data block of the data holder, and configure block index identifier for the data block; Based on the data structure characteristics of the data block, a policy mapping is performed on the data block to obtain the reversible transformation policy of the data block; Based on the reversible transformation strategy, the data block is subjected to independent format transformation to obtain the transformed data of the data holding end; Based on the block index identifier and the reversible transformation strategy, construct the restoration mapping information of the data holding end.

[0021] When performing data segmentation on the raw data of the data holder, all the raw data stored on the data holder is first obtained. According to the actual data length and data storage logic of the raw data, the raw data is divided into several fixed-size and non-overlapping data segments. Each data segment is a data block of the data holder. After the segmentation is completed, a unique identifier is assigned to each data block as a block index identifier. The block index identifier corresponds one-to-one with the corresponding data block, and the corresponding single data block can be quickly located through the block index identifier, ensuring that each data block has a unique and identifiable identifier. Finally, all the data blocks of the data holder and the block index identifier corresponding to each data block are obtained.

[0022] When performing policy mapping on data blocks based on their data structure characteristics, the data structure characteristics of each data block are first parsed one by one. These characteristics include the data type, data organization, and internal relationships of the data. After parsing, a preset policy mapping rule is invoked. This rule is a mapping relationship of corresponding reversible transformation strategies pre-defined according to different data structure characteristics. The parsed data structure characteristics of the data blocks are precisely matched with the preset policy mapping rule. If a match is successful, the unique reversible transformation strategy corresponding to the data block is determined, and finally, the reversible transformation strategy corresponding to each data block is obtained.

[0023] When performing independent format transformation on data blocks based on a reversible transformation strategy, a separate reversible transformation strategy is invoked for each data block. The storage format and data presentation of the data block are converted according to the format transformation method specified by the reversible transformation strategy. The requirements of the reversible transformation strategy are strictly followed during the transformation process to ensure that each transformed data block can be restored to the original data block through the corresponding reversible transformation strategy. Moreover, the transformation process of each data block is independent of each other and does not affect the transformation operation of other data blocks. After all data blocks have completed the format transformation, all the transformed individual data blocks are integrated together to obtain the transformed data at the data holding end.

[0024] When constructing the restoration mapping information based on block index identifiers and reversible transformation strategies, the block index identifiers of all data blocks and the reversible transformation strategy corresponding to each block index identifier are first collected. Each block index identifier is then associated and bound with its corresponding reversible transformation strategy to construct an association mapping table. This association mapping table clearly records the specific reversible transformation strategy corresponding to each block index identifier. At the same time, the query method and usage rules of the association mapping table are clearly defined to ensure that the corresponding reversible transformation strategy can be quickly queried through the block index identifier. The correspondence between the transformed data and the original data is realized through this association mapping table, and finally, the restoration mapping information of the data holder is formed. This restoration mapping information can support the subsequent operation of restoring the transformed data to the original data.

[0025] The beneficial effects are that by dividing the original data into blocks and configuring block index identifiers, continuous data can be split into independent management units, which facilitates precise implementation of privacy protection and provides an orderly location basis for subsequent restoration.

[0026] By matching reversible transformation strategies based on data block structure characteristics, appropriate protection methods can be adopted for different data types, which can improve the privacy protection effect while ensuring the feasibility of restoration.

[0027] By performing independent format transformations on data blocks based on a reversible transformation strategy, the original private content can be hidden without compromising data usability, achieving a balance between security and practicality.

[0028] By constructing restoration mapping information based on index identifiers and transformation strategies, protection rules can be fully recorded, providing a precise restoration path for subsequent legitimate access and ensuring that data can be recovered normally.

[0029] S2: After associating the transformed data with the data identifier of the data holder, upload it to the data sharing platform, and after associating the restored mapping information with the data identifier, store it in the secure execution environment; In this embodiment of the invention, the step of associating the transformed data with the data identifier of the data holder and then uploading it to the data sharing platform includes: The data structure features of the transformed data are subjected to feature mapping to obtain the data fingerprint of the transformed data; The data fingerprint and data identifier are hash-bound together to obtain the associated mapping metadata of the transformed data; The associated mapping metadata is embedded into the metadata section of the transformed data, and together with the data payload section of the transformed data, they are encapsulated into a data object carrying the data identifier; The data object is transmitted to the data sharing platform, and the associated mapping metadata embedded in the data object is parsed in the data sharing platform; Extract the data identifier and the storage address of the data object, and construct an index mapping table entry between the data identifier and the storage address; The index mapping table entry is written into the retrieval directory of the data sharing platform, so that the retrieval directory can locate the data object using the data identifier.

[0030] The step of associating the restored mapping information with the data identifier and storing it in a secure execution environment includes: The data structure of the restored mapping information is parsed to extract the set of mapping entries in the restored mapping information; Based on the mapping entry set and the data identifier, construct a binding relationship record for the restored mapping information; The binding relationship record is encapsulated into a secure storage object, and the secure storage object is submitted to the secure execution environment; In the secure execution environment, allocate independent storage space for the secure storage object and set access control policies for the independent storage space; The mapping logic of the binding relationship record is written into the access control policy, and an permission anchor point is established between the binding relationship record and the data identifier according to the access control policy; Based on the permission anchor, the restoration mapping information is associated with the data identifier and stored in the secure execution environment.

[0031] Feature mapping processing is carried out on the data structure characteristics of the transformed data. By extracting structural features such as the arrangement of each field, data type distribution, and data hierarchy relationship in the transformed data, the above structural features are transformed into unique corresponding identification information according to the preset feature mapping rules, and finally the data fingerprint of the transformed data is obtained.

[0032] The obtained data fingerprint is associated with the original data identifier corresponding to the data holder by using a hash binding method. During the binding process, the complete contents of the data fingerprint and the data identifier are read in sequence, and the contents of the two are concatenated and integrated in an orderly manner before a hash operation is performed to make the data fingerprint and the data identifier form an inseparable association, thereby obtaining the associated mapping metadata of the transformed data.

[0033] The generated associated mapping metadata is embedded into the pre-divided metadata segment of the transformed data, while the original data payload segment of the transformed data that carries the actual business content is retained. The metadata segment and the data payload segment are integrated and encapsulated according to the established encapsulation rules to form a complete data object carrying a data identifier.

[0034] The encapsulated data object is transmitted to the data sharing platform via a network transmission channel. After receiving the data object, the data sharing platform parses the overall structure of the data object according to the preset parsing rules, and locates and extracts the associated mapping metadata embedded in the metadata segment.

[0035] Extract the corresponding original data identifier from the parsed associated mapping metadata, and at the same time obtain the actual storage address allocated to the data object by the data sharing platform. Match the extracted data identifier with the obtained storage address to construct an index mapping table entry that corresponds one-to-one between the data identifier and the storage address.

[0036] The completed index mapping table entries are written into the preset search directory of the data sharing platform, so that the search directory can use data identifiers as the search basis to quickly locate and find the actual storage location of the corresponding data object in the data sharing platform.

[0037] According to the preset structural parsing rules, the overall data structure of the restored mapping information is decomposed layer by layer, the hierarchical division and content distribution within the restored mapping information are identified in turn, and all the mapping-related content contained therein is extracted one by one and integrated to form a complete set of mapping entries.

[0038] The extracted mapping entry set is matched and associated with the corresponding data identifier one by one. The contents of the two are integrated in an orderly manner according to fixed association rules, and the correspondence between the mapping entry set and the data identifier is completely recorded to form a binding relationship record that restores the mapping information.

[0039] The generated binding relationship records are encapsulated in accordance with the security encapsulation specification to remove redundant information and unify the data format, forming a secure storage object that meets the security storage requirements. The secure storage object is then submitted to the secure execution environment through a specified transmission channel.

[0040] After receiving a secure storage object, the secure execution environment allocates a dedicated storage area for it, assigns an independent storage space that is isolated from other storage content, and formulates dedicated access control rules for this independent storage space according to security control rules, thus completing the setting of access control policies.

[0041] The mapping logic contained in the binding relationship record is completely written into the configured access control policy, so that the access control policy can identify the association attribute between the mapping relationship and the data identifier. Then, according to the management rules of the access control policy, a unique permission association node is established between the binding relationship record and the data identifier, forming a permission anchor point.

[0042] Using the generated permission anchor as the basis for association, the restored mapping information and data identifier are stably associated according to the established correspondence, and then the complete associated content is stored in the allocated independent storage space within the secure execution environment.

[0043] The beneficial effects are that feature mapping of transformed data yields data fingerprints, which uniquely identify the data entity, effectively preventing data tampering and replacement, and providing a reliable and unforgeable characteristic basis for subsequent association and binding. Binding data fingerprints with data identifier hashes to generate association mapping metadata establishes a strong association between data and identity, ensuring that data in the shared platform is traceable, verifiable, and associative.

[0044] Embedding association mapping metadata into metadata segments and encapsulating it as data objects allows for the integrated storage of identifiers and transformation data, preventing the loss of associations and improving the integrity of data management. Uploading and parsing the association mapping metadata of the data objects enables the rapid extraction of core association information, providing an accurate basis for the platform to build indexes and simplifying subsequent data location and retrieval processes.

[0045] Constructing an index mapping table of data identifiers and storage addresses enables rapid data retrieval and location, significantly improving the data retrieval efficiency and access response speed of the sharing platform. Writing the index mapping table entries into the search directory allows the platform to directly locate target data using data identifiers, simplifying the sharing access process and improving the overall efficiency of privacy data sharing.

[0046] Parsing and restoring the data structure of the mapping information and extracting the mapping entry set allows for the complete breakdown of the core content of the restoration rules. This provides standardized and complete foundational data for subsequent secure binding, ensuring the traceability of the restoration logic. Constructing binding relationship records based on the mapping entry set and data identifiers establishes a unique correspondence between restored information and data identity, preventing the abuse or mismatch of restoration rules and enhancing privacy control security.

[0047] Encapsulating binding relationship records into secure storage objects and submitting them to a secure execution environment isolates and protects critical restoration information, preventing the leakage of mapping data during transmission and storage. Allocating independent storage space to these secure storage objects and setting access control policies enables dedicated, isolated storage of restoration information, preventing unauthorized access and significantly improving the storage security of sensitive mapping data.

[0048] By incorporating the mapping logic of binding relationship records into access control policies and establishing permission anchors, access permissions are strongly bound to data identities, enabling fine-grained permission management and enhancing the controllability of the secure execution environment. By associating restoration mapping information with data identifiers through permission anchors, it ensures that restoration information can only be accessed by legitimate entities, achieving secure storage of data and restoration rules separately, and reducing the risk of data leakage.

[0049] S3: Authenticate the data access request from the data requesting end and generate a temporary access credential for the data requesting end, wherein the temporary access credential contains authorization policy information; In this embodiment of the invention, the step of authenticating the data access request from the data requesting end and generating a temporary access credential for the data requesting end, wherein the temporary access credential contains authorization policy information, including: Receive a data access request submitted by a data requester, and extract the identity authentication factor of the data requester from the data access request, wherein the identity authentication factor includes the identity identifier and digital signature of the data requester; The identity authentication factor is submitted to the identity authentication service in the secure execution environment, and the identity authentication service is invoked to perform a signature verification operation on the digital signature to obtain the identity authentication result of the identity authentication factor; When the authentication result is successful, obtain the authorization policy information of the data requesting end; Based on the authentication result and the authorization policy information, construct the main data structure of the temporary access credential; The identity identifier and the authorization policy information are written into the main data structure, and the main data structure is encrypted to obtain the encrypted credential body of the identity authentication factor; The encrypted credential body is combined and encapsulated with the hash value of the identity identifier to obtain the temporary access credential of the data requesting end.

[0050] The system receives a data access request initiated and submitted by the data requester. According to the preset information extraction rules, it extracts and obtains the identity verification-related content from the message content carried in the access request, and obtains the identity authentication factor of the data requester. The identity authentication factor completely includes the identity identifier of the data requester and the digital signature used to verify the legitimacy.

[0051] The extracted authentication factors are submitted to the authentication service deployed and running within the secure execution environment through a secure and reliable transmission channel. This triggers and calls the authentication service to execute the signature verification process. The authentication service retrieves the pre-stored verification criteria to verify the integrity and legality of the digital signature item by item. After the verification is completed, the authentication result corresponding to the authentication factor is output.

[0052] If the authentication result returned by the authentication service is that the verification is successful, retrieve the permission control content that matches the current data request client from the preset authorization management library, and obtain the authorization policy information corresponding to the data request client.

[0053] Based on the successful identity verification results and the obtained authorization policy information, the overall framework of the temporary access credential is built in accordance with the credential generation specification. The arrangement and storage location of each field inside the credential are determined, and the main data structure of the temporary access credential is constructed.

[0054] The identity identifier and corresponding authorization policy information of the data requester are sequentially filled into the corresponding field positions of the main data structure. After filling, the entire main data structure is encrypted using the specified encryption method, so that the main data structure is converted into an encrypted form that cannot be directly read, and the encrypted credential body corresponding to the identity authentication factor is obtained.

[0055] The generated encrypted credential body and the hashed identity of the data requester are sequentially concatenated and encapsulated to form a complete and unified credential, ultimately yielding the temporary access credential corresponding to the data requester.

[0056] The beneficial effects are that by receiving data access requests and extracting identity authentication factors, the legitimate identity credentials of the requesting party can be accurately obtained, providing a true and complete basis for subsequent identity verification and ensuring the credibility of the access source.

[0057] Submitting the identity authentication factor to a secure execution environment for verification can strictly verify the legitimacy of the requester's identity, effectively prevent access by forged identities, and improve the access security of data sharing.

[0058] After successful authentication, authorization policy information is obtained, which can accurately match the corresponding permission scope of the requesting party, providing a compliant permission basis for subsequent credential generation and data access. Constructing the credential body structure based on the verification results and authorization policy standardizes the composition of temporary access credentials, ensuring that the credential content is complete and meets the requirements for subsequent verification and use.

[0059] By incorporating and encrypting the identity identifier and authorization policy into the main structure, core credential information can be protected from theft and tampering, ensuring the security of access permissions and the transmission and storage of identity information. Encapsulating the encrypted credential body with the identity identifier hash value further enhances the credential's anti-counterfeiting capabilities, ensuring that temporary access credentials are unique and cannot be forged, thus improving access control security.

[0060] S4: Submit the temporary access credential to the secure execution environment and call the access control contract in the secure execution environment to verify the temporary access credential; In this embodiment of the invention, submitting the temporary access credential to the secure execution environment and invoking the access control contract in the secure execution environment to verify the temporary access credential includes: Submit the temporary access credentials to the decryption service in the secure execution environment; Based on the decryption service, the temporary access credential is restored and decrypted to obtain the requester's identity, authorization policy information, and credential validity period information of the temporary access credential. The requester's identity, the authorization policy information, and the credential validity period information are transmitted to the access control contract in the secure execution environment. Based on the access control contract, the identity identifier, authorization policy information, and credential validity period information of the requesting party are verified to obtain the verification result of the temporary access credential.

[0061] Temporary access credentials are submitted to the decryption service deployed within the secure execution environment via a dedicated data transmission interface. During transmission, the environment’s internal security protection mechanisms ensure that the content of the temporary access credentials is not tampered with or leaked, and is transmitted intact to the decryption service.

[0062] The decryption service is started and its internal preset decryption logic is invoked. The decryption service first disassembles the outer encapsulation of the temporary access credential, and then restores and decrypts the encrypted content inside the credential layer by layer according to the preset decryption method, gradually removing all encryption protection of the credential. Finally, the requester's identity identifier, authorization policy information and credential validity information are accurately extracted from the decrypted credential content, ensuring that the three types of information extracted are completely consistent with the original content in the temporary access credential.

[0063] Through a trusted interaction channel within the secure execution environment, the decrypted requester's identity, authorization policy information, and credential validity information are completely transmitted to the access control contract pre-deployed within the secure execution environment. During transmission, the data is verified in real time to ensure that the three types of information are not lost or deviated during transmission and are completely transmitted to the verification module of the access control contract.

[0064] The access control contract is initiated and its internal preset verification logic is invoked. First, the legitimacy of the requester's identity is verified to confirm that the requester corresponding to the identity is an authorized legitimate entity. Then, the validity of the authorization policy information is verified to confirm that the authorization policy information has not expired, has not been tampered with, and meets the requirements of the current access scenario. Finally, the compliance of the credential validity period information is verified to confirm that the temporary access credential is still within its valid period. The results of the three verifications are summarized and integrated to finally obtain the verification result of the temporary access credential.

[0065] The beneficial effect is that submitting temporary access credentials to the decryption service of the secure execution environment allows decryption operations to be performed in a trusted environment, preventing credential information from being stolen or tampered with during transmission and parsing.

[0066] By restoring and decrypting credentials through the decryption service, the identity identifier, authorization policy information, and credential validity period information of the requesting party can be completely extracted, providing an accurate and complete data foundation for contract verification.

[0067] The extracted three types of information are transmitted to the access control contract, which enables trusted data transfer within a secure execution environment, ensuring the authenticity and integrity of the data source.

[0068] By verifying identity, authorization policies, and validity periods based on access control contracts, multi-level security verification can be achieved, accurately determining the legitimacy of access and improving the overall security of data sharing.

[0069] S5: After successful verification, extract the mapping subset corresponding to the authorization strategy information from the restoration mapping information according to the authorization strategy information; In this embodiment of the invention, after the verification is passed, a subset of mappings corresponding to the authorization policy information is extracted from the restored mapping information according to the authorization policy information, including: Based on the verification results, extract the scope of the authorization data identifier and the permission level of the data field from the authorization policy information; Extract the complete mapping entry associated with the data identifier from the restored mapping information; Based on the authorized data identifier range, the complete mapping entries are filtered at the first level to obtain the first filtering result of the restored mapping information; Based on the data field permission level, the first filtering result is filtered at a second level to obtain the second filtering result of the restored mapping information; According to the complete mapping entries, the second filtering results are sorted and assembled to obtain the mapping subset of the restored mapping information.

[0070] Based on the verification result of the temporary access credential, after confirming the completeness and validity of the authorization policy information, the authorization policy information is decomposed according to the preset information extraction rules. The scope of the authorization data identifier and the permission level of the data field are accurately extracted to ensure that the two pieces of information extracted are completely consistent with the authorization policy information without any omissions.

[0071] Retrieve the restoration mapping information associated with the data identifier of the current data requesting end stored in the secure execution environment. Parse the restoration mapping information layer by layer according to its storage structure, extract all the mapping associations contained therein, and integrate them to form a complete mapping entry corresponding to the data identifier, ensuring that the complete mapping entry covers all the associated content in the restoration mapping information.

[0072] Using the extracted authorized data identifier range as the first-level filtering criterion, the obtained complete mapping entries are compared and filtered one by one. Mapping content that does not match the authorized data identifier range is removed from the complete mapping entries, and mapping entries that meet the requirements of the authorized data identifier range are retained. Finally, the first filtering result of restoring the mapping information is obtained.

[0073] The extracted data field permission levels are used as the second-level filtering criteria. Permission verification is performed on each mapping entry in the first filtering result to determine whether the data field permissions of each mapping entry meet the requirements of the data field permission level. Mapping entries with mismatched permissions are removed, and mapping entries with the required permissions are retained to obtain the second filtering result of restoring the mapping information.

[0074] Referring to the original arrangement logic and association order of the complete mapping entries, the mapping entries in the second screening results are organized in an orderly manner. The second screening results are sorted according to the arrangement rules of the complete mapping entries. At the same time, the sorted mapping entries are integrated and assembled to ensure that the assembled content is logically coherent and structurally complete, and finally a mapping subset that restores the mapping information is obtained.

[0075] The beneficial effect is that by extracting the authorized data identifier range and data field permission level based on the verification results, the scope of legal access can be accurately located, providing a clear compliance basis for subsequent mapping information screening.

[0076] By extracting the complete mapping entries associated with the data identifier from the restoration mapping information, we can comprehensively obtain the basic data of the restoration rules and ensure that no key restoration information is missed during the screening process.

[0077] The first-level filtering based on the authorized data identifier range can quickly filter irrelevant mapping content, narrow down the range of valid information, and improve the efficiency of subsequent permission matching and restoration processing.

[0078] A second level of filtering based on data field permission levels allows for strict adherence to permission boundaries, limiting available data for restoration and enabling refined permission control to prevent unauthorized data access. Assembling the second-level filtering results into a mapping subset, ordered by complete mapping entries, ensures an orderly and standardized restoration logic, providing reliable support for subsequent accurate and secure data restoration.

[0079] S6: Based on the mapping subset and the data identifier, perform a reverse restoration operation on the transformed data to obtain the target data of the data requesting end, and return the target data to the data requesting end.

[0080] In this embodiment of the invention, the step of performing a reverse restoration operation on the transformed data based on the mapping subset and the data identifier to obtain the target data of the data requesting end, and returning the target data to the data requesting end, includes: Parse the mapping subset and extract the data block index identifier and restoration path information from the mapping subset; Based on the data identifier, locate and obtain the transformation data associated with the data identifier from the data sharing platform, and parse the transformation data block corresponding to the data block index identifier from the transformation data; Based on the restoration path information, the transformed data block is subjected to a reverse transformation operation to obtain the restored data block of the data requesting end; Based on the order of the data block index identifiers, the restored data blocks are spliced ​​and assembled to obtain the target data of the data requesting end; The target data is encapsulated into a response message, and the response message is returned to the data requesting end.

[0081] The step of performing a reverse transformation operation on the transformed data block based on the restoration path information to obtain the restored data block from the data requesting end includes: The restoration path information is parsed to obtain the transformation mode identifier, transformation parameters, and integrity check value of the restoration path information. Based on the transformation mode identifier, determine the reverse transformation logic of the restoration path information; Based on the transformation parameters, the transformed data block is subjected to inverse transformation processing to obtain the initial restored data block of the data requesting end; The integrity of the initial restored data block is verified using the integrity check value to obtain the restored data block from the data requesting end.

[0082] According to the preset parsing rules, the overall structure of the mapping subset is decomposed layer by layer. The internal relationships and content distribution of the mapping subset are identified in turn. The data block index identifiers and restoration path information contained therein are extracted one by one to ensure that the two pieces of information extracted are complete and completely correspond to the content of the mapping subset without any omissions or deviations.

[0083] Using data identifiers as the retrieval basis, the retrieval directory of the data sharing platform is retrieved. The transformed data associated with the data identifier is located through the index mapping table entries already constructed in the retrieval directory. The transformed data is retrieved from the corresponding storage address of the data sharing platform. Then, it is parsed according to the storage structure of the transformed data, and the transformed data blocks corresponding one-to-one with the extracted data block index identifiers are obtained.

[0084] Using the extracted restoration path information as the basis for the reverse transformation operation, the obtained transformed data block is processed in reverse according to the steps and logic specified in the restoration path information. The transformation process experienced by the transformed data block is gradually removed, and the transformed data block is restored to the original data form, finally obtaining the restored data block corresponding to the data request end.

[0085] The original order of the extracted data block index identifiers is sorted out and used as the basis for splicing and assembly. All restored data blocks are connected and integrated in this order to ensure that adjacent restored data blocks are connected and consistent in data logic. After complete splicing and assembly, the target data required by the data request end is formed.

[0086] According to the preset response message encapsulation specification, the obtained target data is used as the core content, and the basic identification information required for the response is added. The target data is uniformly encapsulated to form a complete response message. Then, through a secure and reliable network transmission channel, the response message is transmitted to the data requesting end that initiated the data access request, ensuring that the target data is returned securely and completely.

[0087] The restoration path information is fully decomposed according to the preset parameter parsing rules. Each parameter contained in the restoration path information is identified and extracted one by one. The transformation mode identifier, transformation parameters and integrity check value are accurately separated to ensure that the three types of information extracted are complete and correspond completely with the original content in the restoration path information without any deviation.

[0088] Using the extracted transformation mode identifier as the core basis, the system retrieves the pre-defined correspondence database between transformation modes and reverse transformation logic. By comparing the transformation mode identifier with various identifier information in the database, the system determines the reverse transformation logic that uniquely matches the transformation mode identifier, and clarifies the specific steps, sequence, and operation standards of the reverse transformation operation.

[0089] Using a defined reverse transformation logic as the operating principle, the extracted transformation parameters are integrated into the entire reverse transformation process. Following the steps specified by the reverse transformation logic, the obtained transformed data blocks are processed in reverse one by one, gradually undoing the transformation process previously experienced by the transformed data blocks, restoring the transformed data blocks to their initial original data form, and obtaining the initial restored data block corresponding to the data request end.

[0090] The extracted integrity check value is used as the verification standard to perform a comprehensive integrity check on the obtained initial restored data block. Each item of the initial restored data block is compared with the standard requirements corresponding to the integrity check value. It is confirmed that the initial restored data block has no missing data, no tampering, and no damage. After the verification is passed, the initial restored data block is the restored data block corresponding to the data request end.

[0091] The beneficial effect is that by parsing the mapping subset and extracting the data block index identifier and restoration path information, the positioning and operation basis required for restoration can be accurately obtained, providing stable support for subsequent reverse data restoration.

[0092] By locating transformed data based on data identifiers and parsing out the corresponding transformed data blocks, the target data fragments can be quickly retrieved, avoiding interference from irrelevant data and improving the targeting and efficiency of the restoration process. Performing a reverse transformation operation on the transformed data blocks based on the restoration path information allows for the restoration of the original data form according to rules, ensuring data integrity and usability while protecting privacy and security.

[0093] By assembling and reconstructing data blocks according to their block index identifiers, the data structure remains consistent with the original logic, preventing errors and data loss, and ensuring the integrity and accuracy of the target data. Encapsulating the target data into a response message and returning it to the data requesting end standardizes the data output format, ensures secure and reliable transmission, and enables end-to-end privacy-protected data sharing.

[0094] By parsing the restoration path information, the transformation mode identifier, transformation parameters, and integrity verification values ​​are obtained. This allows for a complete breakdown of the core elements of the restoration rules, providing a precise and comprehensive basis for the reverse transformation. Based on the transformation mode identifier, the reverse transformation logic is determined, accurately matching the reverse operation rules corresponding to the forward transformation. This ensures a standardized and reliable restoration process and guarantees the accuracy of data recovery.

[0095] By performing inverse transformation on the transformed data block according to the transformation parameters, the data format can be restored strictly according to preset rules, ensuring that the initial restored data block is consistent with the original content. Verifying the initial restored data block with an integrity check value can effectively identify data loss, tampering, and corruption, ensuring that the final output restored data block is authentic, complete, and usable.

[0096] like Figure 2 The diagram shown is a functional block diagram of a privacy-protected data sharing system provided in an embodiment of the present invention.

[0097] The privacy-preserving data sharing system described in this invention can be installed in an electronic device. Depending on the functions implemented, the privacy-preserving data sharing system may include a data protection module, a separate storage module, an authentication module, a credential verification module, an on-demand retrieval module, and a data restoration module. The module described in this invention can also be referred to as a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and perform a fixed function, and are stored in the memory of the electronic device.

[0098] In this embodiment, the functions of each module / unit are as follows: The data protection module is used to perform reversible privacy protection processing on the original data of the data holder to obtain the transformed data of the data holder and the corresponding restoration mapping information. The separate storage module is used to associate the transformed data with the data identifier of the data holder and upload it to the data sharing platform, and to associate the restored mapping information with the data identifier and store it in the secure execution environment. The authentication module is used to authenticate the data access request from the data requesting end and generate a temporary access credential for the data requesting end. The temporary access credential contains authorization policy information. The credential verification module is used to submit the temporary access credential to the secure execution environment and call the access control contract in the secure execution environment to verify the temporary access credential. The on-demand extraction module is used to extract a subset of mappings corresponding to the authorization policy information from the restored mapping information after the verification is passed, based on the authorization policy information. The data restoration module is used to perform a reverse restoration operation on the transformed data according to the mapping subset and the data identifier to obtain the target data of the data requesting end, and return the target data to the data requesting end.

[0099] In the several embodiments provided by this invention, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0100] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0101] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0102] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0103] This application embodiment can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence is the theory, method, technology, and application system that uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use that knowledge to obtain optimal results.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A privacy-preserving data sharing method, characterized in that, The method includes: S1: Perform reversible privacy protection processing on the original data held by the data holder to obtain the transformed data and corresponding restoration mapping information of the data holder, including: Perform data block operation on the original data of the data holder to obtain the data block of the data holder, and configure block index identifier for the data block; Based on the data structure characteristics of the data block, a policy mapping is performed on the data block to obtain the reversible transformation policy of the data block; Based on the reversible transformation strategy, the data block is subjected to independent format transformation to obtain the transformed data of the data holding end; Based on the block index identifier and the reversible transformation strategy, construct the restoration mapping information of the data holding end; S2: After associating the transformed data with the data identifier of the data holder, upload it to the data sharing platform, and after associating the restored mapping information with the data identifier, store it in the secure execution environment; S3: Authenticate the data access request from the data requesting end and generate a temporary access credential for the data requesting end, wherein the temporary access credential contains authorization policy information; S4: Submit the temporary access credential to the secure execution environment and call the access control contract in the secure execution environment to verify the temporary access credential; S5: After successful verification, extract the mapping subset corresponding to the authorization strategy information from the restoration mapping information according to the authorization strategy information; S6: Based on the mapping subset and the data identifier, perform a reverse restoration operation on the transformed data to obtain the target data of the data requesting end, and return the target data to the data requesting end.

2. The privacy-preserving data sharing method as described in claim 1, characterized in that, The step of associating the transformed data with the data identifier of the data holder and then uploading it to the data sharing platform includes: The data structure features of the transformed data are subjected to feature mapping to obtain the data fingerprint of the transformed data; The data fingerprint and data identifier are hashed together to obtain the associated mapping metadata of the transformed data; The associated mapping metadata is embedded into the metadata section of the transformed data, and together with the data payload section of the transformed data, they are encapsulated into a data object carrying the data identifier; The data object is transmitted to the data sharing platform, and the associated mapping metadata embedded in the data object is parsed in the data sharing platform; Extract the data identifier and the storage address of the data object, and construct an index mapping table entry between the data identifier and the storage address; The index mapping table entry is written into the retrieval directory of the data sharing platform, so that the retrieval directory can locate the data object using the data identifier.

3. The privacy-preserving data sharing method as described in claim 2, characterized in that, The step of associating the restored mapping information with the data identifier and storing it in a secure execution environment includes: The data structure of the restored mapping information is parsed to extract the set of mapping entries in the restored mapping information; Based on the mapping entry set and the data identifier, construct a binding relationship record for the restored mapping information; The binding relationship record is encapsulated into a secure storage object, and the secure storage object is submitted to the secure execution environment; In the secure execution environment, allocate independent storage space for the secure storage object and set access control policies for the independent storage space; The mapping logic of the binding relationship record is written into the access control policy, and an permission anchor point is established between the binding relationship record and the data identifier according to the access control policy; Based on the permission anchor, the restoration mapping information is associated with the data identifier and stored in the secure execution environment.

4. The privacy-preserving data sharing method as described in claim 1, characterized in that, The process involves authenticating the data access request from the data requesting client and generating a temporary access credential for the data requesting client. This temporary access credential contains authorization policy information, including: Receive a data access request submitted by a data requester, and extract the identity authentication factor of the data requester from the data access request, wherein the identity authentication factor includes the identity identifier and digital signature of the data requester; The identity authentication factor is submitted to the identity authentication service in the secure execution environment, and the identity authentication service is invoked to perform a signature verification operation on the digital signature to obtain the identity authentication result of the identity authentication factor; When the authentication result is successful, obtain the authorization policy information of the data requesting end; Based on the authentication result and the authorization policy information, construct the main data structure of the temporary access credential; The identity identifier and the authorization policy information are written into the main data structure, and the main data structure is encrypted to obtain the encrypted credential body of the identity authentication factor; The encrypted credential body is combined and encapsulated with the hash value of the identity identifier to obtain the temporary access credential of the data requesting end.

5. The privacy-preserving data sharing method as described in claim 1, characterized in that, The step of submitting the temporary access credential to the secure execution environment and invoking the access control contract in the secure execution environment to verify the temporary access credential includes: Submit the temporary access credentials to the decryption service in the secure execution environment; Based on the decryption service, the temporary access credential is restored and decrypted to obtain the requester's identity, authorization policy information, and credential validity period information of the temporary access credential. The requester's identity, the authorization policy information, and the credential validity period information are transmitted to the access control contract in the secure execution environment. Based on the access control contract, the identity identifier, authorization policy information, and credential validity period information of the requesting party are verified to obtain the verification result of the temporary access credential.

6. The privacy-preserving data sharing method as described in claim 5, characterized in that, After the verification is successful, based on the authorization policy information, a subset of mappings corresponding to the authorization policy information is extracted from the restored mapping information, including: Based on the verification results, extract the scope of the authorization data identifier and the permission level of the data field from the authorization policy information; Extract the complete mapping entry associated with the data identifier from the restored mapping information; Based on the authorized data identifier range, the complete mapping entries are filtered at the first level to obtain the first filtering result of the restored mapping information; Based on the data field permission level, the first filtering result is filtered at a second level to obtain the second filtering result of the restored mapping information; According to the complete mapping entries, the second filtering results are sorted and assembled to obtain the mapping subset of the restored mapping information.

7. The privacy-preserving data sharing method as described in claim 1, characterized in that, The step of performing a reverse restoration operation on the transformed data based on the mapping subset and the data identifier to obtain the target data of the data requesting end, and returning the target data to the data requesting end, includes: Parse the mapping subset and extract the data block index identifier and restoration path information from the mapping subset; Based on the data identifier, locate and obtain the transformation data associated with the data identifier from the data sharing platform, and parse the transformation data block corresponding to the data block index identifier from the transformation data; Based on the restoration path information, the transformed data block is subjected to a reverse transformation operation to obtain the restored data block of the data requesting end; Based on the order of the data block index identifiers, the restored data blocks are spliced ​​and assembled to obtain the target data of the data requesting end; The target data is encapsulated into a response message, and the response message is returned to the data requesting end.

8. The privacy-preserving data sharing method as described in claim 7, characterized in that, The step of performing a reverse transformation operation on the transformed data block based on the restoration path information to obtain the restored data block from the data requesting end includes: The restoration path information is parsed to obtain the transformation mode identifier, transformation parameters, and integrity check value of the restoration path information. Based on the transformation mode identifier, determine the reverse transformation logic of the restoration path information; Based on the transformation parameters, the transformed data block is subjected to inverse transformation processing to obtain the initial restored data block of the data requesting end; The integrity of the initial restored data block is verified using the integrity check value to obtain the restored data block from the data requesting end.

9. A privacy-preserving data sharing system, characterized in that, The system for implementing the privacy-preserving data sharing method of claim 1 includes: The data protection module is used to perform reversible privacy protection processing on the original data of the data holder to obtain the transformed data of the data holder and the corresponding restoration mapping information. A separate storage module is used to associate the transformed data with the data identifier of the data holder and upload it to the data sharing platform, and to associate the restored mapping information with the data identifier and store it in a secure execution environment; An authentication module is used to authenticate the data access request from the data requesting end and generate a temporary access credential for the data requesting end, wherein the temporary access credential contains authorization policy information. The credential verification module is used to submit the temporary access credential to the secure execution environment and call the access control contract in the secure execution environment to verify the temporary access credential. The on-demand extraction module is used to extract the mapping subset corresponding to the authorization policy information from the restoration mapping information after the verification is passed, based on the authorization policy information. The data restoration module is used to perform a reverse restoration operation on the transformed data according to the mapping subset and the data identifier to obtain the target data of the data requesting end, and return the target data to the data requesting end.

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