CN116305266A - Data query method and device based on privacy protection - Google Patents

Abstract

The embodiment of this specification provides a data query method and device based on privacy protection, involving the query party and the data party, the data party holds multiple POIs distributed in the geographical space, the geographical space is divided into multiple partitions, and a single A partition is divided into subspaces. The querying party can determine the target partition to which the target location to be queried belongs to from multiple partitions, determine m target subspaces whose distance from the target location is within a preset range from the target partition, and send the user to the data side A query request for querying POIs, which includes indication information for indicating the target partition; the query side can base on the identification of m target subspaces, and the data side can jointly perform N selection m based on the identification of N subspaces included in the target partition. The OT protocol enables the query side to obtain POI information located in m target subspaces from the data side.

Description

Data query method and device based on privacy protection

technical field

One or more embodiments of this specification relate to the computer field, and in particular to a data query method and device based on privacy protection.

Background technique

Data query based on geographic location is an important part of geographic information services. For example, the inquiring party can send the target location to be queried to the geographic information service system provided by the geographic information service provider. ), determine the POIs whose distance from the target position is within a certain preset range, and then return the determined POIs to the querying party.

It is hoped that there will be a new technical solution in order to realize data query based on geographical location more safely and efficiently.

Contents of the invention

One or more embodiments of this specification provide a data query method and device based on privacy protection.

In the first aspect, a data query method based on privacy protection is provided, involving a query party and a data party, the data party holds multiple POIs distributed in a geographical space, and the geographical space is divided into multiple partitions, A single said partition is divided into multiple subspaces. The method includes: the inquiring party determines from the multiple partitions the target partition to which the target location to be queried belongs, and determines from the target partition that the distance to the target location is within a preset range m target subspaces within; the query direction sends a query request for POI query to the data party, which includes indication information for indicating the target partition; the query party based on the m target subspaces based on the identifiers of the N subspaces included in the target partition, the data party jointly executes an oblivious transfer (oblivious transfer, OT) protocol in which N selects m, so that the query party obtains POIs.

In a possible implementation manner, the query side is based on the identification of the m target subspaces, and the data side is based on the identification of the N subspaces included in the target partition, and jointly executes the OT protocol where N selects m , including: the query direction sends m first ciphertexts to the data party, the m first ciphertexts are first keys based on an exchangeable encryption algorithm, and encrypt the identifiers of the m target subspaces obtained; the data party encrypts the m first ciphertexts according to the second key of an exchangeable encryption algorithm to obtain m second ciphertexts; the data party sends the m ciphertexts to the querying party second ciphertexts and N data ciphertexts, the N data ciphertexts are obtained by encrypting POIs in the N subspaces according to N symmetric keys, and the N symmetric keys are obtained according to The second key of the exchangeable encryption algorithm is obtained by encrypting the identifiers of the N subspaces; the querying party decrypts the m second ciphertexts according to the decryption key corresponding to the first key , to obtain m third ciphertexts; the querying party uses the m third ciphertexts as decryption keys, and performs m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts Decryption is performed to obtain POIs in the m target subspaces.

In a possible implementation manner, the identification of the subspace includes k numbers belonging to k categories; wherein, the querying side is based on the identification of the m target subspaces, and the data side is based on the target The identifiers of the N subspaces included in the partition, jointly execute the OT protocol where N selects m, including: the query party acquires k first ciphertext sets and sends them to the data party, and the k first ciphertext sets The ciphertext set is obtained by encrypting the numbers belonging to the k categories in the identifiers of the m target subspaces according to the k first keys of the exchangeable encryption algorithm; The k second keys of the algorithm encrypt the k first ciphertext sets to obtain k second ciphertext sets; the data direction sends the k second ciphertext sets and N data ciphertexts, the N data ciphertexts are obtained by encrypting POIs in the N subspaces according to N symmetric keys, and the jth symmetric key is obtained according to the k second keys , obtained by encrypting the k numbers included in the identifier of the j-th subspace; the querying party performs the k second ciphertext set according to the k decryption keys corresponding to the k first keys Decrypt to obtain k third ciphertext sets; the querying party extracts ciphertext elements from the k third ciphertext sets according to the identifiers of the m target subspaces, and combines them to generate the m target subspaces m ciphertext groups corresponding to the space; the querying party uses the m ciphertext groups as symmetric keys to perform m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts Decrypt to obtain POIs in the m target subspaces.

In a possible implementation manner, the querying party extracts ciphertext elements from the k third ciphertext sets according to the identifiers of the m target subspaces, and combines them to generate the m target subspace corresponding The m ciphertext groups specifically include: the query party for any p-th target subspace, according to the number belonging to the i-th category in the identification of the p-th target subspace, from the i-th third The ciphertext elements corresponding to the p-th target subspace are determined from the ciphertext set; the querying party combines the k ciphertext elements corresponding to the p-th target subspace to obtain a corresponding ciphertext group.

In a possible implementation manner, the geographical space is a two-dimensional space, and the multiple numbers belonging to the multiple categories specifically include that the subspace corresponds to the row number or the column number in the partition to which it belongs.

In a possible implementation manner, the geographic space is divided into multiple partitions based on longitude and latitude, or the geographic space is divided into multiple partitions based on administrative regions.

In the second aspect, a data query method based on privacy protection is provided, involving a query party and a data party, the data party holds multiple POIs distributed in a geographical space, and the geographical space is divided into multiple partitions, A single partition is divided into multiple subspaces, and the method is executed by the querying party. The method includes: determining from the plurality of partitions the target partition to which the target location to be queried belongs, and determining from the target partitions m partitions whose distance to the target location is within a preset range Target subspace; sending a query request for querying POI to the data party, including indication information for indicating the target partition; based on the identification of the m target subspaces, and the data party based on the target Identify the N subspaces included in the partition, and jointly execute the OT protocol of selecting m from N to obtain POIs in the m target subspaces.

In a possible implementation manner, based on the identifiers of the m target subspaces, and the data party based on the identifiers of the N subspaces included in the target partition, jointly execute an OT protocol in which N selects m, including: sending m first ciphertexts to the data party, the m first ciphertexts are obtained by encrypting the identifiers of the m target subspaces according to the first key of an exchangeable encryption algorithm; The data party receives m second ciphertexts and N data ciphertexts, the m second ciphertexts are obtained by encrypting the m first ciphertexts according to the second key of an exchangeable encryption algorithm , the N data ciphertexts are obtained by encrypting POIs in the N subspaces according to N symmetric keys, and the N symmetric keys are based on the second key of the exchangeable encryption algorithm, for obtained by encrypting the identifiers of the N subspaces; according to the decryption key corresponding to the first key, the m second ciphertexts are decrypted to obtain m third ciphertexts; and the m third ciphertexts are obtained The ciphertext is used as a decryption key to decrypt m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, to obtain POIs in the m target subspaces.

In a possible implementation manner, the identification of the subspace includes k numbers belonging to k categories; wherein, the identification based on the m target subspaces is the same as that of the data party based on the target partition The identities of the N subspaces included, jointly execute the OT protocol where N selects m, including: obtaining k first ciphertext sets and sending them to the data party, and the k first ciphertext sets are based on The k first keys of the exchangeable encryption algorithm are obtained by encrypting the numbers belonging to the k categories in the identifiers of the m target subspaces respectively; receiving k second ciphertext sets from the data party and N data ciphertexts, the k second ciphertext sets are obtained by encrypting the k first ciphertext sets according to the k second keys of the exchangeable encryption algorithm, and the N data encryption The text is obtained by encrypting POIs in the N subspaces according to N symmetric keys, and the jth symmetric key is the k included in the identification of the jth subspace according to the k second keys. obtained by encrypting the numbers; according to the k decryption keys corresponding to the k first keys, the k second ciphertext sets are decrypted to obtain k third ciphertext sets; according to the m The identification of the target subspace, extracting ciphertext elements from the k third ciphertext sets, and combining to generate m ciphertext groups corresponding to the m target subspaces; using the m ciphertext groups as symmetric encryption key, decrypting m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, and obtaining POIs in the m target subspaces.

In a possible implementation manner, according to the identifiers of the m target subspaces, ciphertext elements are extracted from the k third ciphertext sets, and combined to generate m corresponding to the m target subspaces. A ciphertext group specifically includes: for any p-th target subspace, according to the number belonging to the i-th category in the identification of the p-th target subspace, determine from the i-th third ciphertext set A ciphertext element corresponding to the p-th target subspace; combining k ciphertext elements corresponding to the p-th target subspace to obtain a corresponding ciphertext group.

In the third aspect, a data query method based on privacy protection is provided, involving a query party and a data party, the data party holds multiple POIs distributed in a geographical space, and the geographical space is divided into multiple partitions, The single partition is divided into multiple subspaces, and the method is executed by the data party. The method includes: receiving a query request for querying POIs from the querying party, including indication information for indicating a target partition, and the target partition is a target partition determined by the querying party from the plurality of partitions to be The partition to which the target location of the query belongs; based on the identifiers of the N subspaces included in the target partition, and based on the identifiers of the m target subspaces with the querying party, jointly execute an OT protocol in which N selects m, so that the querying party Obtain POIs in the m target subspaces, where the target subspace is a subspace determined by the querying party from the target partition and whose distance from the target location is within a preset range.

In a possible implementation manner, based on the identification of the N subspaces included in the target partition, and the query party based on the identification of the m target subspaces, jointly execute the OT protocol of selecting m from N, including: Receive m first ciphertexts from the querying party, the m first ciphertexts are obtained by encrypting the identifiers of the m target subspaces according to the first key of an exchangeable encryption algorithm; according to the exchangeable encryption algorithm Encrypting the m first ciphertexts with the second key of the encryption algorithm to obtain m second ciphertexts; sending the m second ciphertexts and N data ciphertexts to the querying party, the The N data ciphertexts are obtained by encrypting the POIs in the N subspaces according to N symmetric keys, and the N symmetric keys are based on the second key of the exchangeable encryption algorithm for the N subspaces. obtained by encrypting the identity of the space, so that the querying party decrypts the m second ciphertexts to obtain m third ciphertexts according to the decryption key corresponding to the first key, and converts the m The third ciphertext is used as a decryption key to decrypt m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts to obtain POIs in the m target subspaces.

In a possible implementation manner, the identification of the subspace includes k numbers belonging to k categories; wherein, the identification based on the N subspaces included in the target partition is the same as that of the querying party based on m The identifiers of the target subspaces, and jointly execute the OT protocol where N selects m, including: receiving k first ciphertext sets from the data party, and the k first ciphertext sets are k according to the exchangeable encryption algorithm The first key is obtained by encrypting the numbers belonging to the k categories in the identifiers of the m target subspaces respectively; according to the k second keys of the exchangeable encryption algorithm, the k first The ciphertext set is encrypted to obtain k second ciphertext sets; the k second ciphertext sets and N data ciphertexts are sent to the querying party, and the N data ciphertexts are based on N symmetric ciphertexts. key obtained by encrypting the POIs in the N subspaces, and the j symmetric key is obtained by encrypting the k numbers included in the identification of the j subspace according to the k second keys, so that The querying party decrypts the k second ciphertext sets according to the k decryption keys corresponding to the k first keys to obtain k third ciphertext sets, and according to the m target Space identification, extracting ciphertext elements from the k third ciphertext sets, combining to generate m ciphertext groups corresponding to the m target subspaces, and using the m ciphertext groups as symmetric keys , decrypting m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts to obtain POIs in the m target subspaces.

In the fourth aspect, a data query method based on privacy protection is provided, involving a query party and a data party, the data party holds multiple feature data distributed in a multi-dimensional feature space, and the multi-dimensional feature space is divided into multiple partitions, and a single partition is divided into multiple subspaces. The method includes: the inquiring party determines from the plurality of partitions the target partition to which the target feature to be queried belongs, and determines from the target partition that the distance to the target feature is within a preset range m target subspaces within; the query direction sends a query request for feature data query to the data party, which includes indication information for indicating the target partition; the query party based on the m target subspaces The identification of the space, the data side is based on the identification of the N subspaces included in the target partition, and jointly executes the OT protocol where N selects m, so that the query side obtains the information in the m target subspaces from the data side feature data.

In the fifth aspect, a data query device based on privacy protection is provided, involving a query party and a data party, the data party holds multiple POIs distributed in a geographical space, and the geographical space is divided into multiple partitions, A single partition is divided into multiple subspaces, and the device is deployed on the query side. The device includes: a space determination unit configured to determine from the plurality of partitions the target partition to which the target location to be queried belongs, and determine from the target partition that the distance between the target location and the target location is within a preset distance. m target subspaces within the range; the request sending unit is configured to send a query request for querying the POI to the data party, including indication information used to indicate the target partition; a security communication unit is configured to be based on The identifiers of the m target subspaces and the data party jointly execute an OT protocol in which N selects m based on the identifiers of the N subspaces included in the target partition, to obtain POIs in the m target subspaces.

In the sixth aspect, a data query device based on privacy protection is provided, involving a query party and a data party, the data party holds multiple POIs distributed in a geographical space, and the geographical space is divided into multiple partitions, A single partition is divided into multiple subspaces, and the device is deployed on the data side. The device includes: a request receiving unit configured to receive a query request from the querying party for querying POIs, including indication information for indicating a target partition, and the target partition is obtained from the plurality of POIs by the querying party. The partition to which the target location to be queried is determined in the partition; the security communication unit is configured to jointly execute with the querying party based on the identifiers of the N subspaces included in the target partition, based on the identifiers of the m target subspaces N selects m OT protocol, so that the inquiring party obtains the POIs in the m target subspaces, and the target subspace is the distance between the inquiring party and the target position determined from the target partition Subspaces within a preset range.

In a seventh aspect, a computer-readable storage medium is provided, on which computer programs/instructions are stored, and when the computer programs/instructions are executed in a computing device, the computing device implements any one of the second or third aspects. described method.

In an eighth aspect, a computing device is provided, including a memory and a processor, wherein executable code is stored in the memory, and when the processor executes the executable code, any one of the second or third aspects is implemented. the method described.

With the methods and devices provided in one or more embodiments of this specification, by dividing the geographical space into multiple partitions and dividing a single partition into multiple subspaces, when the query party expects the distance between the query and the target location to be within a preset When the POI is within the range, it can determine the target partition to which the target location to be queried belongs to from multiple partitions, and then determine m target subspaces whose distance from the target location is within the preset range from the target partition , and send a query request to the data party for querying POIs, including indication information for indicating the target partition; furthermore, the query party can be based on the identification of m target subspaces, and the data party can be based on the N subspaces included in the target partition Space identification, jointly execute the OT protocol where N selects m, so that the query party can obtain POIs located in the m target subspaces from the data party. In this way, in the process of querying the POI whose distance from the target location is within the preset range, the data side cannot know the target location queried by the querying side, and the data query based on the geographic location can be implemented more safely and efficiently.

Description of drawings

In order to illustrate the technical solutions of the embodiments of this specification more clearly, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

FIG. 1 is a schematic diagram of a technical scenario provided in an embodiment of this specification;

Fig. 2 is one of the flowcharts of a data query method based on privacy protection provided in the embodiment of this specification;

Fig. 3 is one of the schematic diagrams of the process of jointly executing the OT protocol provided by the querying party and the data party;

4 is a schematic diagram of a single partition divided into a plurality of subspaces in an exemplary provided geographic space;

Fig. 5 is the second schematic diagram of the process of jointly executing the OT protocol provided by the querying party and the data party;

FIG. 6 is the second flowchart of a data query method based on privacy protection provided in the embodiment of this specification;

Fig. 7 is one of the schematic diagrams of a data query device based on privacy protection provided in the embodiment of this specification;

FIG. 8 is the second schematic diagram of a data query device based on privacy protection provided in the embodiment of this specification.

Detailed ways

Various non-limiting embodiments provided in this specification will be described in detail below with reference to the accompanying drawings.

In the geographic information system provided by geographic information service providers, a single POI can represent a house, a shop, a mailbox, a bus stop, etc. distributed in geographic space. A single POI usually contains information on multiple aspects such as name, category, coordinates, and classification, and the coordinates of the POI are used to indicate the corresponding position of the POI in geographic space. The aforementioned geographic space can be a two-dimensional geographic space, and the coordinates of POI can include, for example, its corresponding longitude and latitude in the geographic coordinate system, or can also include its corresponding two-dimensional coordinates in the two-dimensional map coordinate system; the aforementioned geographic The space may also be a three-dimensional geographic space, and the POI coordinates may include, for example, its longitude, latitude, and altitude corresponding to the geographic coordinate system, or may also include its three-dimensional coordinates corresponding to the three-dimensional map coordinate system.

Referring to FIG. 1 , a geographic information service provider may provide a geographic information service system, and the geographic information service system may store multiple POIs distributed in geographic space. When there is a certain user (natural person or organization) who expects to inquire about a POI whose distance from a certain target location in geographic space is within a preset range, it can initiate a query request for POI query to the geographic information service system. The request usually needs to include the target location expected to be queried, so that the geographic information service system can perform a corresponding query and return all POIs whose distances from the target location are within a preset range. However, based on the need for privacy protection, users who inquire about POIs may not wish to expose the target location they expect to inquire about.

The embodiment of this specification provides a data query method and device based on privacy protection. By dividing the geographic space into multiple partitions, and dividing a single partition into multiple subspaces, when the query party expects to query POIs whose distance from the target location is within a preset range, it can determine the POIs to be obtained from multiple partitions. The target partition to which the target location of the query belongs, and then determine m target subspaces whose distance from the target location is within a preset range from the target partition, and send a query request for POI query to the data party, including The indication information used to indicate the target partition; furthermore, the querying party can base on the identification of m target subspaces, and the data side can jointly execute the OT protocol where N selects m based on the identifications of the N subspaces included in the target partition, so that the querying party Obtain the POIs located in the m target subspaces from the data side. In this way, in the process of querying the POI whose distance from the target location is within the preset range, the data side cannot know the target location queried by the querying side, and the data query based on the geographic location can be implemented more safely and efficiently.

FIG. 2 is a flow chart of a data query method based on privacy protection provided in the embodiment of this specification. The method involves two different participants such as a query party and a data party. The data party may correspond to a geographic information service provider providing a geographic information system, and the query party may correspond to a user (including a natural person or an organization) who uses a geographic information system. The query party and the data party can generally each be implemented as any device, platform, device or device cluster with computing/processing capabilities.

The aforementioned data party holds multiple POIs distributed in geographic space. The geographic space is divided into multiple partitions, for example, the geographic space can be divided into multiple partitions based on longitude and latitude, or the geographic space can also be divided into multiple partitions based on administrative regions. A single partition can be divided into multiple subspaces: for example, when the geographical space is a two-dimensional space, a single partition can be gridded according to longitude and latitude to realize the division of a single partition into multiple subspaces, that is, a single subspace is a square or Said to be similar to a square; another example is when the geographical space is a three-dimensional space, a single partition can be divided into multiple subspaces according to longitude, latitude and altitude, that is, a single subspace is a cube or is similar to a cube. The manner of dividing a single partition into multiple subspaces described above is only exemplary, and it can be understood that other manners may also be used to divide the subspaces. It is understood that different partitions may contain different numbers of subspaces.

Referring to Fig. 2, the method may include but not limited to part or all of the following steps S21 to S25.

Step S21, the inquiring party determines the target partition to which the target location to be queried belongs to from multiple partitions in the geographic space, and determines m target subspaces whose distance from the target location is within a preset range from the target partition .

The query side can obtain the location information of the partition and the location information of the subspace. The location information of a single partition is, for example, coordinates of multiple sampling points constituting the boundary/contour of the partition, and the location information of a single subspace is, for example, the coordinates of multiple sampling points constituting the boundary/contour of the subspace. The target partition to which the target location to be queried belongs can be determined from the multiple partitions according to the location information of the multiple partitions, and then determined from the N subspaces included in the target partition according to the location information of the target partition. m target subspaces whose distances between target positions are within a preset range.

In a typical application scenario, the inquiring party can be implemented as a terminal held by the user and deployed with a specific application program. The user can input the aforementioned target location to the terminal through the application program, and then trigger the terminal to implement the aforementioned step S21. The preset range may be pre-configured, or may also be provided by the user according to the user's needs, for example, the user may input the aforementioned preset range into the terminal held by the user through the aforementioned application program.

In step S23, the querying party sends a querying request for querying the POI to the data party, which includes indication information for indicating the target partition. For example, the indication information may be an identifier of the target partition.

Step S25, based on the identifiers of the m target subspaces, and based on the identifiers of the N subspaces included in the target partition, the data provider jointly executes an OT protocol in which N selects m, so that the queryer obtains POIs in the m target subspaces.

The query party and the data party can jointly implement the OT protocol of selecting m from N through various methods.

In a possible implementation manner, as shown in FIG. 3 , the process for the inquiring party and the data party to jointly execute the OT protocol may include part or all of the following steps S301 to S315 .

In step S301, the inquiring party encrypts the identifiers of m target subspaces according to the first key of a commutative encryption algorithm, and obtains m first ciphertexts corresponding to the m target subspaces.

The exchangeable encryption algorithm satisfies E _k1 (E _k2 (L))=E _k2 (E _k1 (L)), where E represents the exchangeable encryption algorithm, k1 and k2 represent two different keys, and L represents the encrypted data . That is, the exchange encryption algorithm is satisfied, and the ciphertext obtained by sequentially encrypting the data L with the key k1 and the key k2 is equivalent to the ciphertext obtained by sequentially encrypting the data L with the key k2 and k1. It is easy to verify. For the ciphertext E _k1 (E _k2 (L)) or E _k2 (E _k1 (L)), the ciphertext E _k2 (L) can be obtained by decrypting the ciphertext with the decryption key d1 corresponding to the key k1. The ciphertext E _k1 (L) can be obtained by decrypting the ciphertext with the decryption key d2 corresponding to the key k2. The exchangeable encryption algorithm can usually be an asymmetric encryption algorithm, such as the SRA algorithm or the Pohlig Hellman algorithm. At this time, the aforementioned decryption key d1 is different from the key k1, and the aforementioned decryption key d2 is different from the key k2; when the exchangeable encryption algorithm In the case of a symmetric encryption algorithm, the aforementioned decryption key d1 is the same as the key k1, and the aforementioned decryption key d2 is the same as the key k2.

That is, the query party holds the first key of the exchangeable encryption algorithm E (such as the aforementioned key k1), and for any p-th target subspace among the m target subspaces, the query party can use the exchangeable encryption algorithm E Encrypt the identity H _p of the p-th target subspace with the key k1 to obtain the first ciphertext E _k1 (H _p ) corresponding to the p-th target subspace.

The aforementioned step S301 is optional. For example, the querying party may encrypt the identifiers of all subspaces belonging to the geographic space in advance according to the first key of the exchangeable encryption algorithm, and obtain the first ciphertexts corresponding to all the subspaces belonging to the geographic space. Correspondingly, in the process of jointly executing the OT protocol of selecting m from N with the data party, the inquiring party does not need to perform the aforementioned step S301, but obtains the corresponding first secrets of all the subspaces belonging to the geographic space in advance. Herein, m first ciphertexts corresponding to the aforementioned m target subspaces are obtained.

Step S303, the query party sends m first ciphertexts to the data party.

Step S305, the data party encrypts m first ciphertexts according to the second key of the exchangeable encryption algorithm to obtain m second ciphertexts.

That is, the data party holds the second key of the exchangeable encryption algorithm E (such as the aforementioned key k2), and for any p-th first ciphertext E _k1 (H _p ) among the m first ciphertexts, the data party The p-th first ciphertext E _k1 (H _p ) can be encrypted according to the key k2 of the exchangeable encryption algorithm E to obtain the p-th second ciphertext E _k2 (E _k1 (H _p )).

In step S307, the data party encrypts the identifiers of the N subspaces included in the target partition according to the second key of the exchangeable encryption algorithm to obtain N symmetric keys.

That is, for any jth subspace in the N subspaces, the data party can encrypt the identity H _j of the jth subspace according to the second key of the exchangeable encryption algorithm E, and obtain the symmetric Key E _k2 (H _j ).

In step S309, the data party performs symmetric encryption on POIs in N subspaces according to N symmetric keys to obtain N data ciphertexts.

That is, according to the symmetric key E _k2 (H _j ) corresponding to the jth subspace, the data party can perform symmetric encryption on all POIs distributed in the jth subspace (denoted as R _i ), and obtain the jth subspace The corresponding j-th data ciphertext F(E _k2 (H _j ), R _j ), where the aforementioned F represents the symmetric encryption algorithm adopted.

The aforementioned step S307 and step S309 are optional. For example, for any partition among the multiple partitions belonging to geographic space, the data party can encrypt the identifiers of the multiple subspaces included in the partition in advance according to the second key of the exchangeable encryption algorithm to obtain the subspaces included in the partition. The symmetric keys corresponding to each of the multiple subspaces, and then according to the symmetric keys corresponding to the multiple subspaces, perform symmetric encryption on all POIs distributed in the corresponding subspaces, and obtain multiple data encryption keys corresponding to the multiple subspaces. arts. Correspondingly, in the process of jointly executing the OT protocol of selecting m from N with the querying party, the data party does not need to perform the aforementioned steps S307 and S309, but obtains all data ciphertexts of the target partition from the data ciphertexts obtained in advance by the data party. N data ciphertexts corresponding to the N subspaces included.

In step S311, the data sends m second ciphertexts and N data ciphertexts to the querying party.

Step S313, the inquiring party decrypts the m second ciphertexts according to the decryption key corresponding to the first key of the exchangeable encryption algorithm, and obtains m third ciphertexts.

That is, for any p-th second ciphertext E _k2 (E _k1 (H _p )) among the m second ciphertexts, the querying party can decrypt the key according to the key k1 of the exchangeable encryption algorithm held by it. The key d1 decrypts the p-th second ciphertext E _k2 (E _k1 (H _p )), and correspondingly obtains the p-th third ciphertext E _k2 (H _p ).

In step S315, the inquiring party uses the m third ciphertexts as decryption keys to decrypt the m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, and obtain the POIs in the m target subspaces.

Referring to the above, the p-th third ciphertext E _k2 (H _p ) obtained by the query party is the same as the one obtained by encrypting the identity H _p of the p-th target subspace by the data party according to the key k2 of the exchangeable encryption algorithm result. For any j-th data ciphertext F(E _k2 (H _j ), R _j ) among the N data ciphertexts obtained by the querying party, it is the symmetric key E _k2 (H _j ) of the data party according to the symmetric encryption algorithm F , is obtained by performing symmetric encryption on R _j (POIs distributed in the jth subspace). It is not difficult to understand that when H _p is the same as H _j , the query party can use the third ciphertext E _k2 (H _p ) as a symmetric key, and for the corresponding data ciphertext F(E _k2 (H _j ), R _j ) for correct decryption. In this way, it can be ensured that the query party cannot obtain too many POIs in other subspaces of the target partition when the POIs distributed in m target subspaces can be obtained.

In a possible implementation manner, the identification of the subspace includes k numbers belonging to k categories, where k is greater than 1.

Referring to Fig. 4, assuming that the geographical space is a two-dimensional geographical space including dimension x and dimension y, it can be divided between dimension x (corresponding to longitude or a dimension in the two-dimensional map coordinate system) and dimension y (corresponding to latitude or two-dimensional map On another dimension in the coordinate system), multiple subspaces belonging to the same partition are numbered. That is, for a single partition, the partition can be gridded according to the dimension x and the dimension y so as to divide the partition into multiple subspaces of the same size or similar in size; Numbering (the category of this number is expressed as row coordinates or row number, for example), and a single subspace is numbered on dimension y (the category of this number is expressed as column coordinates or column number, for example), and the subspace corresponds to the partition to which it belongs The numbers of the two categories, such as the row number and the column number, can constitute the identification of the subspace. Based on a similar principle, subspaces can also be used to correspond to the number of the positive diagonal (or expressed as the main diagonal) and the number of the anti-diagonal (or expressed as the sub-diagonal) in the partition to which it belongs. Numbers make up the identity of this subspace. Alternatively, the identification of the subspace can also be composed of four categories of numbers corresponding to the row number, column number, positive diagonal number, and anti-diagonal number in the partition to which the subspace belongs.

The foregoing description of the k numbers of the identified k categories constituting the subspace is exemplary. For example, for a three-dimensional geographic space including dimension x, dimension y, and dimension z, multiple subspaces belonging to the same partition can also be separately numbered on the three dimensions of dimension x, dimension y, and dimension z; In this way, the identifier of a single subspace may be composed of three numbers corresponding to three dimensions of dimension x, dimension y, and dimension z.

In the case where the identification of the subspace includes k numbers belonging to k categories, as shown in FIG. 5, the process of jointly executing the OT protocol where N is selected by m by the querying party and the data party may include the following steps S501 to S517. all.

In step S501, the inquiring party obtains k first ciphertext sets, which are obtained by encrypting numbers belonging to k categories among the identifiers of m target subspaces according to k first keys of an exchangeable encryption algorithm.

The querying party holds k first keys of the exchangeable encryption algorithm E, and the k first keys correspond to the aforementioned k categories.

The inquiring party can encrypt the numbers in the k number sets corresponding to the k categories according to the k first keys of the exchangeable encryption algorithm, and obtain the aforementioned k first ciphertext sets. A single number set consists of m targets The ID of a subspace consists of numbers belonging to the same category. Wherein, for any i-th numbering set, it includes all numbers belonging to the i-th category among the identifications of the m target subspaces. Referring to FIG. 4 , assuming that in the target partition shown in FIG. 4 , the circle of the circular area is the target position, all the subspaces involved in the circular area are m target subspaces. Then, the k numbering sets, for example, may include a column numbering set consisting of column numbers 5-13 and a row numbering set consisting of row numbers 4-12; or may include a pair of positive diagonal numbers 15-27. A set of diagonal numbers and a set of anti-diagonal numbers composed of anti-diagonal numbers 10 to 22; or it can include the aforementioned four numbers, such as the row number set, column number set, positive diagonal number set, and anti-diagonal number set gather.

The first key corresponding to the i-th category is recorded as key k1i, then for the i-th number set, any t-th _number it included in it can be encrypted according to the key k1i, and the t-th first The ciphertext element E _k1i (i _t ), and then use the first ciphertext elements corresponding to the numbers included in the i-th numbering set to form the i-th first ciphertext set C _1i .

For any partition in multiple partitions belonging to geographic space, assuming that the number of numbers belonging to any i-th category in the identifiers of the multiple subspaces included in the partition is T, the data party can also pre-according to the exchangeable encryption algorithm. The i first key respectively encrypts T numbers belonging to the i-th category to obtain an i-th original ciphertext set composed of T original ciphertext elements corresponding to the T numbers. Correspondingly, in the aforementioned step S501, for any i-th category, the inquiring party can select the i-th original ciphertext set from the i-th original ciphertext set according to the numbers belonging to the i-th category in the identifiers of the m target subspaces A number of original ciphertext elements corresponding to a number of numbers form the i-th first ciphertext set.

In step S503, the query sends k first ciphertext sets to the data party.

In step S505, the data party encrypts the k first ciphertext sets according to the k second keys of the exchangeable encryption algorithm to obtain k second ciphertext sets.

The inquiring party holds k second keys of the exchangeable encryption algorithm E, and the k second keys correspond to the aforementioned k categories.

Denote the second key corresponding to the i-th category as key k2i, then for the i-th first ciphertext set C _1i , any t-th first ciphertext element E _k1i included in it can be based on the key k2i (i _t ) to encrypt to obtain the t-th second ciphertext element E _k2i (E _k1i (i _t )), and then use all the first ciphertext elements included in the i-th first ciphertext set C _1i The corresponding second ciphertext elements form the i-th second ciphertext set C _2i .

Step S507, for any j-th subspace among the N subspaces included in the target partition, the data party identifies the k-th subspaces included in the j-th subspace according to the k second keys of the exchangeable encryption algorithm. The k numbers are encrypted to obtain the jth symmetric key corresponding to the jth subspace.

The second key corresponding to the i-th category is recorded as key k2i. Then, for the number H _ji belonging to the i-th category included in the identity H _j of the j-th subspace, it can be encrypted according to the key k2i to obtain the i-th numbered ciphertext E _k2i ( H _ji ); furthermore, k numbered ciphertexts corresponding to the jth subspace can be used to combine and generate the jth symmetric key corresponding to the jth subspace. For the convenience of description, the jth symmetric key is recorded here as is E _k (H _j ).

In step S509, the data party performs symmetric encryption on the POIs in the N subspaces according to the N symmetric keys corresponding to the N subspaces, and obtains N data ciphertexts.

The data party can perform symmetric encryption on all POIs (denoted as R _j ) distributed in the jth subspace according to the jth symmetric key E _k (H _j ) corresponding to the jth subspace, and obtain the jth subspace The corresponding j-th data ciphertext F(E _k (H _j ), R _j ), wherein the aforementioned F represents the symmetric encryption algorithm adopted.

The aforementioned step S507 and step S509 are optional. For example, for any partition among the multiple partitions belonging to the geographical space, the data party can perform the same steps as above step S507 and step S509 is a similar process, obtaining multiple data ciphertexts corresponding to multiple subspaces included in the partition. Correspondingly, in the process of jointly executing the OT protocol of selecting m from N with the data party, the data party does not need to perform the aforementioned steps S507 and S509, but obtains the target partition from all the data ciphertexts obtained in advance by the data party N data ciphertexts corresponding to the N subspaces included.

In step S511, the data sends k second ciphertext sets and N data ciphertexts to the querying party.

Step S513, the querying party decrypts the k second ciphertext sets according to the k decryption keys corresponding to the k first keys, and obtains k third ciphertext sets.

For any t-th second ciphertext element E _k2i (E _k1i (i _t )) included in any i-th second ciphertext set C _2i , it can be decrypted according to the i-th corresponding to the k first keys The key decrypts _it to obtain the tth third ciphertext element E _k2i (i _t ), and then use the corresponding third The ciphertext elements form the i-th third ciphertext set C _3i .

In step S515, the querying party extracts ciphertext elements from k third ciphertext sets according to the identifiers of the m target subspaces, and combines them to generate m ciphertext groups corresponding to the m target subspaces.

For any p-th target subspace, the query party can determine the p-th target from the i-th third ciphertext set C _3i according to the number belonging to the i-th category in the identification of the p-th target subspace The ciphertext elements corresponding to the subspace (the third ciphertext element), and then k ciphertext elements corresponding to the p-th target subspace are combined to obtain the corresponding ciphertext group.

Referring to FIG. 4 , assuming that the k categories include row numbers and column numbers, the querying party can obtain two third ciphertext sets corresponding to row numbers and column numbers. Then, for any p-th target subspace, assuming that it includes row number 5 and column number 7: the arrangement position of row number 5 in the corresponding row number set is 2, so it can be obtained from the third corresponding to the row number set In the ciphertext set, it is determined that the ciphertext element corresponding to the target subspace is the second ciphertext element (i.e. the second third ciphertext element); similarly, the third ciphertext element corresponding to the column number set can be In the set, it is determined that the ciphertext element corresponding to the target subspace is the third ciphertext element (ie, the third third ciphertext element).

For the k ciphertext elements corresponding to the p-th target subspace, the method of obtaining the j-th symmetric key corresponding to the j-th subspace in the example of step S507 above can be used to use the p-th target subspace corresponding to The k ciphertext elements/numbered ciphertext are combined to generate the pth ciphertext group corresponding to the pth subspace which will be used as the symmetric key.

In step S517, the querying party uses m ciphertext groups as symmetric keys to decrypt m data ciphertexts corresponding to m target subspaces among N data ciphertexts, and obtain POIs in m target subspaces.

Referring to the above, the pth ciphertext group (denoted as E _k (H _p )) obtained by the querying party is obtained by the querying party according to the k third ciphertext elements E _k2i (i _t ) corresponding to the pth target subspace Generated by combination, it is the number belonging to the i-th category in the identity of the p _- th target subspace. For any j-th data ciphertext among the N data ciphertexts obtained by the querying party, it is the j-th symmetric key E _k (H _j ) corresponding to the j-th subspace of the data party, and the pairs distributed in the j-th subspace All POIs (denoted as R _j ) in a subspace are symmetrically encrypted to obtain the jth data ciphertext F(E _k (H _j ), R _j ), and the jth symmetric key E _k (H _j ) It is generated by the data party using k numbered ciphertexts E _k2i (H _ji ) corresponding to the jth subspace. It is not difficult to understand that when the identity H _p of the p-th target subspace is the same as the identity H _i of the i-th subspace, the p-th ciphertext group E k (H p ) obtained by the query party is the same as the j-th ciphertext group E _k (H _p ) a symmetric key E _k (H _j ), in this case the query party can use the p-th ciphertext group E _k (H _p ) as a symmetric key, for the corresponding data ciphertext F(E _k2 (H _j ), R _j ) for correct decryption. In this way, it can be ensured that the query party cannot obtain too many POIs in other subspaces when it can obtain POIs distributed in m target subspaces. At the same time, the two parties do not need to perform a large number of exchangeable during the joint execution of the OT protocol. The encryption and decryption processing process of the encryption algorithm is conducive to more efficient realization of data query based on geographic location.

Based on the same idea, the technical solutions provided in the embodiments of this specification can also be extended from geographic space to non-geographic space, for example, to feature space including multiple dimensions to solve similar technical problems. Correspondingly, the embodiment of this specification also provides a data query method based on privacy protection in a multi-dimensional feature space. As shown in Figure 6, this method involves the query side and the data side, where the data side holds multiple feature data distributed in the multi-dimensional feature space, the multi-dimensional feature space is divided into multiple partitions, and a single partition is divided into multiple subspaces . The query party and the data party can generally each be implemented as any device, platform, device or device cluster with computing/processing capabilities.

Referring to Fig. 6, the method may include part or all of the following steps S61 to S65.

Step S61, the inquiring party determines the target partition to which the target feature to be queried belongs to from multiple partitions of the feature space, and determines m objects whose distance to the target feature is within a preset range from the target partition subspace.

In step S63, the query direction sends a query request for querying feature data to the data party, including indication information for indicating the target partition.

Step S65, based on the identifiers of the m target subspaces, and based on the identifiers of the N subspaces included in the target partition, the data side jointly executes the OT protocol where N selects m, so that the query side obtains m target subspaces from the data side feature data in the space.

For the process of jointly executing the OT protocol by the inquiring party and the data party in the aforementioned step S65, reference may be made to the exemplary process described above in relation to FIG. 3 and FIG. 5 , which will not be repeated here.

In this technical solution, the target feature is similar to the target position described in the foregoing method embodiments, which can be mapped to a feature point in a multi-dimensional feature space; a single feature data distributed in a multi-dimensional feature space is similar to the implementation of the foregoing methods. The POI mentioned in the example may include feature points mapped in the multi-dimensional feature space and other data content associated with the feature points. Through this technical solution, when the inquiring party obtains each characteristic data whose distance from the target feature is within a preset range, the data party cannot know the target feature held by the inquiring party. This technical solution can be applied to a variety of technical scenarios. For example, different feature points correspond to different images. The data content included in the feature data includes, for example, the identification of the corresponding image (such as the name of the task to which the face image belongs, the category to which the image belongs, etc. ), so as to realize the query of other characters similar to the character corresponding to the target feature, classify the image corresponding to the target feature, etc.; for example, different feature points correspond to different genomes, and the data content included in the feature data includes, for example, the corresponding genome. The name of the disease, so as to realize the query of the disease that the person corresponding to the target feature is prone to suffer from.

Based on the same idea as the foregoing method embodiments, the embodiment of this specification also provides a data query device 700 based on privacy protection, which involves the query party and the data party, and the data party holds multiple data distributed in geographical space. POI, the geographic space is divided into multiple partitions, and a single partition is divided into multiple subspaces, and the apparatus 700 is deployed on the query side. Referring to FIG. 7 , the apparatus 700 includes: a space determination unit 701 configured to determine from the plurality of partitions the target partition to which the target location to be queried belongs, and determine from the target partition the m target subspaces whose distance between them is within a preset range; the request sending unit 703 is configured to send a query request for querying POIs to the data party, including indication information for indicating the target partition; The secure communication unit 705 is configured to jointly execute an OT protocol in which N selects m based on the identifiers of the m target subspaces, and the data party based on the identifiers of the N subspaces included in the target partition, to obtain the m POIs in the target subspace.

Based on the same idea as the foregoing method embodiments, the embodiment of this specification also provides a data query device 800 based on privacy protection, which involves the query party and the data party, and the data party holds multiple data distributed in geographical space. POI, the geographic space is divided into multiple partitions, and a single partition is divided into multiple subspaces, and the apparatus 800 is deployed on the data side. Referring to FIG. 8 , the apparatus 800 includes: a request receiving unit 801 configured to receive a query request for querying POIs from the querying party, including indication information for indicating a target partition, and the target partition is the query The partition to which the target position to be queried is determined by the party from the plurality of partitions; the secure communication unit 803 is configured to communicate with the querying party based on m targets based on the identifiers of the N subspaces included in the target partition The identification of the subspace, jointly execute the OT protocol of choosing m from N, so that the query party can obtain the POIs in the m target subspaces, and the target subspace is determined by the query party from the target partition and A subspace in which the distance between the target positions is within a preset range.

Those skilled in the art should be aware that in one or more of the above examples, the functions described in this specification may be implemented by hardware, software, firmware or any combination thereof. When implemented in software, the computer programs corresponding to these functions can be stored in a computer-readable medium or transmitted as one or more instructions/codes on a computer-readable medium, so that the computer programs corresponding to these functions can be read by the computer During execution, the method described in any one of the embodiments of this specification is realized by a computer.

The embodiments of this specification also provide a computer-readable storage medium on which computer programs/instructions are stored. When the computer programs/instructions are executed in a computing device, the querying party in any one of the embodiments of this specification can realize the or method steps performed by the data party.

The embodiment of this specification also provides a computing device, including a memory and a processor, wherein executable codes/instructions are stored in the memory, and when the processor executes the executable codes/instructions, any one of the Method steps performed by the querying party or the data party in the embodiments.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts in each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for relevant parts, please refer to part of the description of the method embodiment.

The foregoing describes specific embodiments of this specification. Other implementations are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Multitasking and parallel processing are also possible or may be advantageous in certain embodiments.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, any modification, equivalent replacement, improvement, etc. made on the basis of the technical solution of the present invention shall be included in the protection scope of the present invention.

Claims (18)

1. A data query method based on privacy protection, involving a query party and a data party, the data party holds a plurality of points of interest POIs distributed in geographical space, the geographical space is divided into multiple partitions, and a single place The partition is divided into a plurality of subspaces, the method includes: The inquiring party determines from the plurality of partitions the target partition to which the target location to be queried belongs, and determines from the target partitions m objects whose distance to the target location is within a preset range subspace; The query direction sends a query request for querying the POI to the data party, including indication information for indicating the target partition; Based on the identifiers of the m target subspaces, the inquiring party jointly executes the inadvertent transfer OT protocol in which N selects m based on the identifiers of the N subspaces included in the target partition, so that the inquiring party from The data side obtains POIs in the m target subspaces. 2. The method of claim 1, wherein, Based on the identifiers of the m target subspaces, the query side, and based on the identifiers of the N subspaces included in the target partition, the data side jointly executes an OT protocol in which N selects m, including: The query direction sends m first ciphertexts to the data party, and the m first ciphertexts are obtained by encrypting the identifiers of the m target subspaces according to the first key of an exchangeable encryption algorithm; The data party encrypts the m first ciphertexts according to the second key of the exchangeable encryption algorithm to obtain m second ciphertexts; The data direction sends the m second ciphertexts and N data ciphertexts to the querying party, and the N data ciphertexts encrypt POIs in the N subspaces according to N symmetric keys obtained, the N symmetric keys are obtained by encrypting the identifiers of the N subspaces according to the second key of an exchangeable encryption algorithm; The querying party decrypts the m second ciphertexts according to the decryption key corresponding to the first key to obtain m third ciphertexts; The querying party uses the m third ciphertexts as decryption keys to decrypt m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, and obtain the m target subspaces POIs within the subspace. 3. The method according to claim 1, the identification of the subspace comprises k numbers belonging to k categories; Wherein, the query side is based on the identification of the m target subspaces, and the data side is based on the identification of the N subspaces included in the target partition, and jointly executes an OT protocol where N selects m, including: The querying party obtains k first ciphertext sets and sends them to the data party, the k first ciphertext sets are k first keys according to an exchangeable encryption algorithm, and the m obtained by encrypting the numbers belonging to the k categories in the identifiers of the target subspaces respectively; The data party encrypts the k first ciphertext sets according to k second keys of an exchangeable encryption algorithm to obtain k second ciphertext sets; The data direction sends the k second ciphertext sets and N data ciphertexts to the querying party, and the N data ciphertexts encrypt POIs in the N subspaces according to N symmetric keys The jth symmetric key is obtained by encrypting the k numbers included in the identity of the jth subspace according to the k second keys; The querying party decrypts the k second ciphertext sets according to the k decryption keys corresponding to the k first keys, and obtains k third ciphertext sets; The querying party extracts ciphertext elements from the k third ciphertext sets according to the identifiers of the m target subspaces, and combines them to generate m ciphertext groups corresponding to the m target subspaces; The querying party uses the m ciphertext groups as a symmetric key to decrypt the m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, and obtains the m target subspaces POIs in the space. 4. The method according to claim 3, wherein the querying party extracts ciphertext elements from the k third ciphertext sets according to the identifications of the m target subspaces, and combines to generate the m m ciphertext groups corresponding to the target subspace, including: For any p-th target subspace, the querying party determines from the i-th third ciphertext set that is consistent with the i-th ciphertext set according to the number belonging to the i-th category in the identifier of the p-th target subspace. Ciphertext elements corresponding to p target subspaces; The querying party combines the k ciphertext elements corresponding to the p-th target subspace to obtain a corresponding ciphertext group. 5. The method according to claim 3, wherein the geographical space is a two-dimensional space, and the multiple numbers belonging to multiple categories specifically include, the subspace corresponds to the row number or the column number in the partition to which it belongs. 6. The method according to any one of claims 1-5, wherein the geographic space is divided into multiple partitions based on longitude and latitude, or the geographic space is divided into multiple partitions based on administrative regions. 7. A data query method based on privacy protection, involving a query party and a data party, the data party holds multiple points of interest POIs distributed in geographical space, the geographical space is divided into multiple partitions, and a single The partition is divided into multiple subspaces, the method is executed by the querying party, and the method includes: Determining the target partition to which the target position to be queried belongs to from the plurality of partitions, and determining m target subspaces whose distance from the target position is within a preset range from the target partition; sending a query request for querying the POI to the data party, including indication information for indicating the target partition; Based on the identities of the m target subspaces, and based on the identities of the N subspaces included in the target partition, the data party and the data party jointly execute the N-choice-m-inadvertent transfer OT protocol to obtain the information in the m target subspaces POIs. 8. The method of claim 7, wherein, The OT protocol based on the identification of the m target subspaces, and the identification of the N subspaces included in the target partition by the data party, jointly executes N selecting m, including: Send m first ciphertexts to the data party, where the m first ciphertexts are obtained by encrypting the identifiers of the m target subspaces according to the first key of an exchangeable encryption algorithm; Receive m second ciphertexts and N data ciphertexts from the data party, where the m second ciphertexts are second keys based on an exchangeable encryption algorithm, and encrypt the m first ciphertexts to obtain The N data ciphertexts are obtained by encrypting POIs in the N subspaces according to N symmetric keys, and the N symmetric keys are second keys based on an exchangeable encryption algorithm, Obtained by encrypting the identifiers of the N subspaces; Decrypting the m second ciphertexts according to the decryption key corresponding to the first key to obtain m third ciphertexts; Using the m third ciphertexts as decryption keys, decrypting the m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, to obtain the m data ciphertexts in the m target subspaces POIs. 9. The method according to claim 7, the identification of the subspace comprises k numbers belonging to k categories; Wherein, based on the identifiers of the m target subspaces, and based on the identifiers of the N subspaces included in the target partition, the data party jointly executes an OT protocol in which N selects m, including: Obtaining k first ciphertext sets and sending them to the data party, the k first ciphertext sets are k first keys according to an exchangeable encryption algorithm, for the m target subspaces obtained by encrypting the numbers belonging to the k categories in the identification of ; Receive k second ciphertext sets and N data ciphertexts from the data party, the k second ciphertext sets are k second keys according to an exchangeable encryption algorithm, and the k first The N data ciphertexts are obtained by encrypting the POIs in the N subspaces according to the N symmetric keys, and the jth symmetric key is obtained according to the k second ciphertexts. Key, obtained by encrypting the k numbers included in the identity of the jth subspace; Decrypting the k second ciphertext sets according to the k decryption keys corresponding to the k first keys to obtain k third ciphertext sets; Extracting ciphertext elements from the k third ciphertext sets according to the identifiers of the m target subspaces, and combining and generating m ciphertext groups corresponding to the m target subspaces; Using the m ciphertext groups as symmetric keys, decrypting m data ciphertexts corresponding to the m target subspaces among the N data ciphertexts, and obtaining POIs in the m target subspaces . 10. The method of claim 9, wherein, According to the identification of the m target subspaces, extracting ciphertext elements from the k third ciphertext sets, and combining to generate m ciphertext groups corresponding to the m target subspaces, specifically including: For any p-th target subspace, according to the number belonging to the i-th category in the identification of the p-th target subspace, determine from the i-th third ciphertext set that is compatible with the p-th target subspace The ciphertext element corresponding to the space; Combining k ciphertext elements corresponding to the p-th target subspace to obtain a corresponding ciphertext group. 11. A data query method based on privacy protection, involving a query party and a data party, the data party holds a plurality of points of interest POIs distributed in a geographical space, the geographical space is divided into multiple partitions, and a single The partition is divided into multiple subspaces, the method is executed by the data party, and the method includes: A query request for POI query is received from the querying party, which includes indication information for indicating a target partition, and the target partition is where the target location to be queried determined by the querying party from the plurality of partitions belongs the partition; Based on the identities of the N subspaces included in the target partition, and based on the identities of the m target subspaces, the inquiring party jointly executes the inadvertent transfer OT protocol in which N selects m, so that the inquiring party obtains the m targets A POI in a subspace, the target subspace is a subspace determined by the querying party from the target partition and the distance between the target location and the target location is within a preset range. 12. The method of claim 11, wherein, The OT protocol based on the identification of N subspaces included in the target partition, and the query party based on the identification of m target subspaces, jointly executes the OT protocol of selecting m from N, including: receiving m first ciphertexts from the querying party, where the m first ciphertexts are obtained by encrypting the identifiers of the m target subspaces according to a first key of an exchangeable encryption algorithm; Encrypting the m first ciphertexts according to a second key of an exchangeable encryption algorithm to obtain m second ciphertexts; Sending the m second ciphertexts and N data ciphertexts to the querying party, the N data ciphertexts are obtained by encrypting POIs in the N subspaces according to N symmetric keys, so The N symmetric keys are obtained by encrypting the identifiers of the N subspaces according to the second key of the exchangeable encryption algorithm, so that the querying party uses the decryption key corresponding to the first key to The m second ciphertexts are decrypted to obtain m third ciphertexts, and the m third ciphertexts are used as decryption keys, and the N data ciphertexts correspond to the m target subspaces The m data ciphertexts are decrypted to obtain the POIs in the m target subspaces. 13. The method according to claim 11, wherein the identification of the subspace comprises k numbers belonging to k categories; Wherein, based on the identifiers of the N subspaces included in the target partition, and the inquiring party based on the identifiers of the m target subspaces, jointly execute the OT protocol of selecting m from N, including: Receive k first ciphertext sets from the data party, the k first ciphertext sets are k first keys according to an exchangeable encryption algorithm, and the identifiers of the m target subspaces belong to all The numbers of the above k categories are obtained by encrypting respectively; Encrypting the k first ciphertext sets according to k second keys of an exchangeable encryption algorithm to obtain k second ciphertext sets; sending the k second ciphertext sets and N data ciphertexts to the querying party, where the N data ciphertexts are obtained by encrypting POIs in the N subspaces according to N symmetric keys, The jth symmetric key is obtained by encrypting the k numbers included in the identification of the jth subspace according to the k second keys, so that the query party uses the k number corresponding to the k first key k decryption keys, decrypting the k second ciphertext sets to obtain k third ciphertext sets, according to the identification of the m target subspaces, from the k third ciphertext sets Extracting ciphertext elements, combining and generating m ciphertext groups corresponding to the m target subspaces, and using the m ciphertext groups as symmetric keys, for the N data ciphertexts corresponding to the m target subspaces The m data ciphertexts corresponding to the subspaces are decrypted to obtain POIs in the m target subspaces. 14. A data query method based on privacy protection, involving a query party and a data party, the data party holds multiple feature data distributed in a multi-dimensional feature space, the multi-dimensional feature space is divided into multiple partitions, and a single The partition is divided into a plurality of subspaces, the method comprising: The inquiring party determines the target partition to which the target feature to be queried belongs to from the plurality of partitions, and determines m targets whose distance from the target feature is within a preset range from the target partition subspace; The query direction sends a query request for querying characteristic data to the data party, including indication information for indicating the target partition; Based on the identifiers of the m target subspaces, the inquiring party jointly executes the inadvertent transfer OT protocol in which N selects m based on the identifiers of the N subspaces included in the target partition, so that the inquiring party from The data party obtains feature data in the m target subspaces. 15. A data query device based on privacy protection, involving a query party and a data party, the data party holds multiple points of interest POIs distributed in a geographical space, the geographical space is divided into multiple partitions, and a single The partition is divided into multiple subspaces, the device is deployed on the query side, and the device includes: A space determination unit configured to determine from the plurality of partitions the target partition to which the target location to be queried belongs, and determine from the target partition that the distance between the target location and the target location is within a preset range m target subspace; A request sending unit configured to send a query request for querying POIs to the data party, including indication information for indicating the target partition; The secure communication unit is configured to jointly execute the inadvertent transfer OT protocol in which N selects m based on the identifiers of the m target subspaces, and the data party based on the identifiers of the N subspaces included in the target partition, to obtain the POIs within m target subspaces. 16. A data query device based on privacy protection, involving a query party and a data party, the data party holds multiple points of interest POIs distributed in a geographical space, the geographical space is divided into multiple partitions, and a single The partition is divided into multiple subspaces, the device is deployed on the data side, and the device includes: A request receiving unit configured to receive a query request for POI query from the querying party, including indication information for indicating a target partition, the target partition is determined by the querying party from the plurality of partitions The partition to which the target location to be queried belongs; The secure communication unit is configured to jointly execute the inadvertent transfer OT protocol of selecting m from N with the inquiring party based on the identifiers of the N subspaces included in the target partition, so that the inquiring party Obtain POIs in the m target subspaces, where the target subspace is a subspace determined by the querying party from the target partition and whose distance from the target location is within a preset range. 17. A computing device, comprising a memory and a processor, wherein executable code is stored in the memory, and when the processor executes the executable code, the method according to any one of claims 7-14 is implemented. 18. A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed in a computing device, the computing device implements the method according to any one of claims 7-14.

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