Dynamic geographic data hierarchical encryption method based on ECIES and spatial index

Abstract

The invention relates to the technical field of geographic information security, and discloses a dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing, which comprises the following steps: carrying out hierarchical processing on dynamic geographic data to obtain a plurality of data layers, constructing or updating a spatial indexing structure corresponding to the plurality of data layers, and encrypting the spatial indexing structure according to the spatial indexing structure. And based on the hierarchical processing result and the spatial index structure, adopting an ECIES encryption algorithm to perform hierarchical encryption processing on the geographic data of each data level, when the dynamic geographic data is updated, adjusting the corresponding data layer according to the update content, the update content including data attribute change, spatial position movement and data format conversion, receiving a decryption request, and sending the decryption request to the corresponding data level. Layering is performed based on data sensitivity, precision and spatial scale, differential encryption is realized and security and efficiency are balanced in combination with an encryption strength dynamic adjustment formula, and through a node splitting and merging mechanism of spatial indexes, only a data layer and an index of a changed part need to be updated, so that full-amount encryption is avoided, and resource consumption is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geographic information security, in particular to a dynamic geographic data hierarchical encryption method based on ECIES and spatial index. BACKGROUND

[0002] With the wide application of geographic information system (GIS), the security of dynamic geographic data (such as real-time traffic data, meteorological monitoring data, urban planning data, etc.) is increasingly valued. Such data has the characteristics of strong spatial correlation, frequent dynamic updating, large data size, etc. The traditional encryption method has the following shortcomings: Insufficient layer encryption: Most encryption methods use a unified encryption strategy without considering the spatial hierarchy, sensitivity and precision difference of geographic data, resulting in insufficient protection of high-sensitive data or redundant encryption of low-sensitive data. Low dynamic update efficiency: When geographic data is updated (such as location movement, attribute change), the traditional method needs to re-encrypt all data or adjust the encryption structure in a large range, which consumes a lot of time and resources. Inadequate combination of spatial query and encryption: When decrypting and querying, all encrypted data needs to be traversed, lacking a fast positioning mechanism based on spatial location, affecting query efficiency. Complex key management: Dynamic data update can easily lead to confusion of the correspondence between keys and data, and traditional key management schemes are difficult to adapt to high-frequency update scenarios. The ECIES algorithm is based on elliptic curve cryptography, with short key length and high security, suitable for geographic data encryption needs; spatial index technology (such as R-tree, quadtree) can efficiently manage the spatial location information of geographic data. The present application combines the two and proposes a hierarchical encryption method to solve the above technical problems. SUMMARY

[0003] The present application provides a dynamic geographic data hierarchical encryption method based on ECIES and spatial index, which solves the problems of insufficient layer encryption, low dynamic update efficiency, inadequate combination of spatial query and encryption, and complex key management of existing encryption methods.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: The dynamic geographic data hierarchical encryption method based on ECIES and spatial index comprises the following steps: S1, performing hierarchical processing on dynamic geographic data to obtain a plurality of data layers, and retaining the spatial correlation and metadata between layers; S2, constructing or updating a spatial index structure corresponding to the data layers, the spatial index structure containing spatial location, range and data volume information; S3, based on the hierarchical results and the spatial index, using the ECIES algorithm to encrypt each data layer, different layers or nodes using different keys; S4, when the dynamic geographic data is updated, adjusting the corresponding data layer and synchronously updating the spatial index and the encryption information; S5, receiving a decryption request, locating the target data based on the spatial index, decrypting and verifying the integrity after verifying the authority. Further, in step S1, the dynamic geographic data includes vector geographic data, raster geographic data and three-dimensional geographic model data, the hierarchical processing is divided by a hierarchical threshold formula, the hierarchical threshold The formula is: , Wherein is the hierarchical threshold of the first layer, is the data sensitivity coefficient, is the data precision coefficient, is the spatial scale coefficient, is the weight coefficient, and . Further, the spatial index structure is one or a combination of R-tree, quadtree, grid index or KD-tree, the minimum circumscribed rectangle of the R-tree node is calculated by the coordinates of the geographic elements in the node, and the quadtree is divided by the midpoint of the coordinates. Further, the encryption strength in step S3 is adjusted by the formula: , wherein is the adjustment coefficient (0 <1), is the hierarchical threshold, and N is the spatial index node depth value. Further, the ECIES encryption in step S3 includes: Key generation: generating an elliptic curve key pair for each data layer or node, the private key satisfies ( is the elliptic curve order), and the public key ( is the base point of the elliptic curve); Encryption execution: encrypting with the public key, and the symmetric key is generated by , wherein , is the receiver's private key, is the sender's public key. Further, after encryption, the data is stored in association with the spatial index node information, and a mapping relationship table of the encrypted data hash value and the node ID is established.

[0005] Furthermore, in step S4, data updates include adding, deleting, and modifying data. When the amount of data in a spatial index node exceeds a threshold... The formula for calculating when a node split is triggered and exceeds the split threshold is:

[0006] in, As the initial threshold, For growth rate, This represents the number of updates.

[0007] Furthermore, the decryption process in S5 includes: Spatial range filtering: Based on the spatial query range in the decryption request, calculate the intersection-union ratio (IUU) between the query range and the index node. ,filter Nodes; Access verification: via formula Verify permissions, among which For permission weights, For the matching result.

[0008] Furthermore, during decryption, a hash function (plaintext + timestamp) is used to verify the integrity and timeliness of the data.

[0009] Furthermore, in step S3, when encrypting using the ECIES algorithm, the topological relationship information of the geographic data is protected. This includes transmitting topological metadata through an independent encrypted channel and adding integrity check codes to the topological association fields. The topological relationship information refers to the spatial relationships between features in the geographic data, including node connectivity, edge adjacency, and polygon containment relationships.

[0010] This invention provides a dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing. This method offers the following advantages: (1) Layered encryption is highly targeted: it is layered based on data sensitivity, accuracy and spatial scale, and combined with the encryption strength dynamic adjustment formula to achieve differentiated encryption and balance security and efficiency. (2) High efficiency of dynamic update: Through the node splitting and merging mechanism of spatial index, only the data level index of the changed part needs to be updated, avoiding full encryption and reducing resource consumption; (3) High efficiency of spatial query: The spatial index is used to quickly locate the target data. Combined with intersection-union ratio filtering and permission matching degree calculation, the decryption query efficiency is improved. (4) Key management security flexibility: the key pair mechanism of ECIES algorithm is adopted, combined with the key management module, to ensure the accurate correspondence of the key and the data layer and the index node, support dynamic key update and revocation; (5) Data integrity protection: through SHA-256 hash function and timestamp verification, the integrity and timeliness of the decrypted data are ensured, and data tampering or expired use is prevented. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 Flowchart of the present application based on ECIES and spatial index dynamic geographic data hierarchical encryption method; Figure 2 Flowchart of the present application based on ECIES and spatial index dynamic geographic data hierarchical encryption system. DETAILED DESCRIPTION

[0012] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described with reference to the accompanying drawings.

[0013] As shown in Figures 1-2 , the present application has the following two specific embodiments.

[0014] Embodiment 1 The method for hierarchical encryption of dynamic geographic data based on ECIES and spatial index includes the following steps: S1, the dynamic geographic data is processed by layering to obtain a plurality of data layers, the dynamic geographic data includes vector geographic data, raster geographic data and three-dimensional geographic model data, and the spatial correlation relationship and metadata information between the data layers need to be retained during the layering process, wherein the calculation formula of the layering threshold is as follows:

[0015] wherein, is the layering threshold of the first layer, is the data sensitivity coefficient (value range 0-1), is the data precision coefficient (value range 0-1), is the spatial scale coefficient (value range 0-1), is the weight coefficient, and ; S2, construct or update the spatial index structure corresponding to the plurality of data layers, the spatial index structure contains the spatial position information, data range and data volume statistical information of the hierarchical geographic data of each data layer, and supports multi-scale spatial query operation; S3, based on the hierarchical processing results and the spatial index structure, using the ECIES encryption algorithm to encrypt the geographical data of each data layer, wherein the geographical data corresponding to different data layers or different spatial index nodes in the same data layer are encrypted using different keys, and the topological relationship information of the geographical data needs to be specially protected during the encryption process, and the encryption strength The calculation formula is:

[0016] Wherein, is an adjustment coefficient , is the depth value of the spatial index node; S4, when the dynamic geographical data is updated, adjust the corresponding data layer according to the update content, the update content includes data attribute change, spatial position movement and data format conversion, trigger node splitting when the data amount of the spatial index node exceeds the threshold The calculation formula for exceeding the splitting threshold is:

[0017] Wherein, is the initial threshold, is the growth rate , is the number of updates, and the index parameters of the spatial index structure and the encryption key and encryption identifier of the corresponding data are updated synchronously; S5, receive decryption request, the decryption request contains requester identity information and spatial query condition, based on the spatial index structure to locate the data layer and the spatial index node where the target data is located, verify the requester identity authority, and the calculation formula of the authority matching degree Is:

[0018] Wherein, is the th authority weight, is the authority matching result (0 or 1), the decryption key corresponding to the target data is used to decrypt through the ECIES decryption algorithm to obtain the decrypted geographical data, and the integrity and timeliness of the data need to be verified through the hash function (plaintext + timestamp) during the decryption process; The hierarchical processing of dynamic geographical data includes: according to at least one of the spatial hierarchical relationship (such as administrative division level, terrain elevation level), data sensitivity level (such as public level, internal level, secret level, confidential level) or data precision requirement (such as 1:1000 scale, 1:5000 scale) of geographical data, combined with the data application scene demand, through the preset hierarchical threshold parameter The dynamic geographic data is divided into multiple data layers, and each data layer contains an independent spatial reference system and data quality description information; The spatial index structure is one or a combination of R-tree index, quadtree index, grid index, or KD-tree index, wherein the minimum circumscribed rectangle of the R-tree index node The calculation formula is as follows:

[0019] wherein, is the minimum circumscribed rectangle, is the coordinate of the geographic element in the node; The quadrant partitioning of the quadtree index determines the partitioning line through the coordinate midpoint, and the calculation formula of the coordinate midpoint is as follows: ; The ECIES encryption algorithm is used to perform hierarchical encryption processing on the geographic data of each data layer, specifically including: The key generation stage: for each data layer or spatial index node, an elliptic curve key pair corresponding to the data layer or spatial index node is generated, and the elliptic curve key pair is generated based on a preset elliptic curve parameter, wherein the private key is used for decryption, and the public key is used for encryption, wherein the private key satisfies ( is the order of the elliptic curve), and the public key ( is the base point of the elliptic curve); The encryption execution stage: the public key is used to encrypt the geographic data in the corresponding data layer or spatial index node, and the symmetric key is generated by , ( is the private key of the receiver, is the public key of the sender), is a key derivation function, is the key length, and the encrypted data is generated; The storage association stage: the encrypted data and the corresponding spatial index node information are stored in association, and a mapping relationship table of the encrypted data hash value and the spatial index node ID is established; When the dynamic geographic data is updated, the corresponding data layer is adjusted according to the update content, and the spatial index structure and the encryption information of the corresponding data are updated, specifically including: New data processing: when new geographic data is added, the data layer to which the new data belongs and the corresponding spatial index node are determined, the new data is encrypted by the ECIES encryption algorithm using the key corresponding to the data layer or the spatial index node, and the spatial index structure is updated; Data deletion processing: When deleting geographic data, delete the corresponding encrypted information and adjust the information of related nodes in the spatial index structure; Data modification processing: When modifying geographic data, the data layer and spatial index node to which the modified data belongs are re-determined. If the layer or node changes, the key corresponding to the new layer or node is used for encryption, and the spatial index structure is updated. Based on the spatial index structure, the data layer and spatial index node where the target data is located are located. The data is then decrypted using the ECIES decryption algorithm with the decryption key corresponding to the target data. Specifically, this includes: Spatial range filtering: Based on the spatial query range in the decryption request, calculate the intersection-union ratio (IUU) between the query range and the index node. ,filter Nodes with a minimum intersection-union ratio (CIU) threshold are selected, meaning nodes with a CIU not lower than a preset threshold (e.g., 0.5). Key acquisition verification: Based on the filtering results, query the key management system and verify the key by using the permission matching formula. Verify permissions; Decryption and Verification: Decrypt the corresponding encrypted data using the verified decryption key, and verify the data integrity using the hash value (plaintext + timestamp).

[0020] Example 2 The difference from Embodiment 1 is that this embodiment discloses a data layered encryption system, such as... Figure 2 As shown: A dynamic geographic data hierarchical encryption system based on ECIES and spatial indexing, which implements any one of the dynamic geographic data hierarchical encryption methods based on ECIES and spatial indexing, including: The data layering module is used to process dynamic geographic data in layers. It has a built-in layering rule base and spatial analysis engine, supports custom layering parameter settings, and outputs multiple data layers containing metadata. The spatial index module is used to build or update spatial index structures corresponding to multiple data layers. The spatial index structure contains spatial location information of geographic data at each data layer. The encryption module is used to perform layered encryption processing on geographic data at each data level based on the layered processing results and spatial index structure, using the ECIES encryption algorithm. It integrates a hardware encryption acceleration unit and supports dynamic adjustment of encryption strength. Geographic data corresponding to different data layers or different spatial index nodes in the same data layer are encrypted using different keys. The dynamic updating module is configured to capture the update content through the updating monitor when the dynamic geographic data is updated, call the data adjustment unit to modify the corresponding data layer, and update the spatial index structure and the encryption information of the corresponding data through the index updating unit and the encryption updating unit in linkage; The decryption query module is configured to receive a decryption request, and includes a request parser, an authority verifier, and a spatial positioning engine. The decryption query module is configured to receive a decryption request, and includes a request parser, an authority verifier, and a spatial positioning engine. The key management module is configured to generate, store, distribute, and revoke the elliptic curve key pair (public key The key management module is configured to generate, store, distribute, and revoke the elliptic curve key pair (public key

[0021] The above merely illustrates the specific implementation of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present application shall fall within the scope of the present application. It should be noted that the components of the present application are not limited to the above overall application, and the technical features described in the specification of the present application can be selected for single use or combined use according to actual needs, therefore, the present application naturally covers other combinations and specific applications related to the present application.

Claims

1. A dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing, characterized in that, Includes the following steps: S1. Dynamic geographic data is processed into multiple data layers by layering, while preserving the spatial relationships and metadata between layers. S2. Construct or update the spatial index structure corresponding to the data layer, wherein the spatial index structure includes spatial location, range and data volume information; S3. Based on the hierarchical results and spatial index, the ECIES algorithm is used to perform hierarchical encryption on each data layer, with different keys used for different layers or nodes; S4. When dynamic geographic data is updated, the corresponding data layer is adjusted and the spatial index and encryption information are updated synchronously. S5. Receive the decryption request, locate the target data based on the spatial index, verify permissions, decrypt and verify integrity.

2. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: In step S1, the dynamic geographic data includes vector geographic data, raster geographic data, and 3D geographic model data. Layering is performed using a layering threshold formula, where the layering threshold is... The formula is: ， in For the first Layer stratification threshold, For data sensitivity coefficient, For data precision coefficients, This is the spatial scale coefficient. These are the weighting coefficients, and .

3. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: The spatial index structure is one or a combination of R-tree, quadtree, grid index, or KD-tree. The minimum bounding rectangle of an R-tree node is calculated from the coordinates of the geographic features within the node. A quadtree divides quadrants by the midpoint of the coordinates.

4. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: Encryption strength in step S3 Through the formula: Adjustments, among which This is an adjustment factor (0 < λ < 1). is the layer threshold, and N is the spatial index node depth value.

5. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: Step S3, ECIES encryption includes: Key generation: Generate elliptic curve key pairs and private keys for each data layer or node. satisfy ( (Elliptic curve order), public key ( (The base point of the elliptic curve). Encryption execution: Encrypted with a public key and a symmetric key. pass Generate, where ,in For the recipient's private key, This is the sender's public key.

6. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 5, characterized in that: After encryption, the data is associated with and stored in relation to spatial index node information, and a mapping table between the hash value of the encrypted data and the node ID is established.

7. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: In step S4, data updates include adding, deleting, and modifying data. When the amount of data in a spatial index node exceeds a threshold... The formula for calculating when a node split is triggered and exceeds the split threshold is: in, As the initial threshold, For growth rate, This represents the number of updates.

8. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: The decryption process in S5 includes: Spatial range filtering: Based on the spatial query range in the decryption request, calculate the intersection-union ratio (IUU) between the query range and the index node. ,filter Nodes; Access verification: via formula Verify permissions, among which For permission weights, The result is the matching result.

9. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: Decryption requires verifying data integrity and timeliness using a hash function (plaintext + timestamp).

10. The dynamic geographic data hierarchical encryption method based on ECIES and spatial indexing according to claim 1, characterized in that: When using the ECIES algorithm for encryption in step S3, the topological relationship information of the geographic data is protected, including transmitting topological metadata through an independent encrypted channel and adding an integrity check code to the topological association field.

Images