Field proof file information encryption tamper-proof method for land change investigation technology

Abstract

The invention relates to the technical field of geographic information processing, in particular to a field proof file information encryption tamper-proof method of a land change investigation technology, which comprises the following steps: using authorization authentication, and initializing a camera; acquiring attitude information of the equipment when the investigator takes a picture, and calculating a direction angle of the picture by combining with geographic position information of the equipment; the positioning map is integrated into the shot picture, and watermarking is carried out on the shot picture; writing the required geographic metadata into an image file of a shot picture, and encoding and packaging according to a standard format; according to the method, the technical requirements of all links are packaged into the SDK, it is guaranteed that the proof file meets the requirements, it is guaranteed that the data of the proof file is encrypted and safely transmitted, operation is convenient and fast, quality is controllable, and the method is easy to implement and popularize. And the land change investigation business field work proof efficiency is improved by more than 40%.

Description

Technical Field

[0001] This invention relates to the field of geographic information processing technology, and in particular to a method for encrypting and preventing tampering of field evidence documents related to land change surveys. Background Technology

[0002] Land use change surveys are a crucial component of national land management and natural resource supervision, and field evidence collection is a core element in ensuring the accuracy of land use change data. Traditional field evidence collection methods rely on handheld devices for taking photos, manually recording location information, and manually exporting the evidence data. This data must then be copied to a computer within a specified network environment before uploading. Manually taking photos and recording location information is susceptible to human error, leading to data distortion and inefficiency. It also fails to quickly capture photos with the parameters and location information required by the technical regulations for land use change surveys. Furthermore, the lack of map references results in inaccurate photo positioning, failing to meet evidence requirements. Due to security concerns regarding sensitive data, some evidence data can only be stored on the mobile devices used for field investigations, making secure transmission to the management platform impossible. In addition, the varying software technology stacks used by different regions lead to inconsistent data formats, complex API integration, and high maintenance costs, hindering long-term data management and verification.

[0003] To meet the standard requirements of the "Technical Specifications for Land Change Survey", an integrated and standardized field evidence SDK (Software Development Kit) is needed, which can also realize data collection, location, encrypted storage and data uploading, so as to improve the accuracy, reliability and security of land change survey data. Summary of the Invention

[0004] The purpose of this invention is to provide a method for encrypting and preventing tampering of field evidence documents in land change survey technology, aiming to achieve data collection, location, encrypted storage, and data uploading, thereby improving the accuracy, reliability, and security of land change survey data.

[0005] To achieve the above objectives, this invention provides a method for encrypting and preventing tampering of field evidence documents in land change survey technology, comprising the following steps;

[0006] Use authorization and authentication to initialize the camera, and customize the camera module parameters and buttons through the mobile app;

[0007] The orientation information of the equipment when the investigators take photos is obtained, and combined with the geographical location information of the equipment, the orientation angle of the photos is calculated using trigonometric functions and vector operations.

[0008] The location map is integrated into the captured photos, and the captured photos are watermarked.

[0009] The system acquires high-precision latitude and longitude coordinates and altitude data when the photo is taken, writes the required geographic metadata into the image file of the photo by calling the Android system, and then encodes and encapsulates the image file according to a standard format.

[0010] The captured photos and survey data are hashed to obtain a data digest, which generates a unique and tamper-proof request code and transmits it to the server for digital signature.

[0011] The camera module's dedicated UI includes an eagle-eye map, a flash switch, a photo button, a video recording button, and a front / rear camera switching button.

[0012] The attitude information includes the heading angle, roll angle, and pitch angle.

[0013] The watermarking process includes the shooting time, shooting direction angle, shooting angle, longitude of the camera positioning module, and longitude of the camera positioning module, which are directly superimposed on the original image in the form of multi-line text.

[0014] The image file should contain longitude, latitude, azimuth, relative altitude, original resolution width-height, 35mm equivalent focal length, shooting date, photographer, certificate code, absolute altitude, roll angle, and pitch angle.

[0015] The present invention discloses a method for encrypting and preventing tampering of field evidence documents in land change survey technology. This method utilizes authorization and authentication, camera initialization, and custom camera module parameters and buttons via a mobile terminal. It acquires the device's posture information when the surveyor takes photos, combines this with the device's geographic location information, and calculates the photo's orientation angle using trigonometric functions and vector operations. A positioning map is integrated into the captured photos, and a watermark is applied. High-precision latitude and longitude coordinates and altitude data at the time of photo capture are obtained. The necessary geographic metadata is written into the image file of the captured photos by calling the Android system, and then the image file is encoded and encapsulated according to a standard format. A hash calculation is performed on the captured photos and survey data to obtain a data digest, generating a unique and tamper-proof request code, which is transmitted to the server for digital signature generation and verification code generation. This method encapsulates the technical requirements of each stage into an SDK, ensuring that the evidence documents comply with the requirements of the "Technical Specifications for Land Change Survey", ensuring that the evidence document data is encrypted and transmitted securely, and that the operation is convenient and the quality is controllable. It improves the efficiency of field evidence collection in land change survey business by more than 40%, and can complete the acquisition and encryption of field evidence photos according to the requirements of land change survey business, ensuring the quality, accuracy and integrity of data and transmission, improving survey efficiency, enhancing data accuracy and reliability and meeting technical specification requirements.

[0016] The beneficial effects are as follows:

[0017] I. Improved efficiency and accuracy throughout the process: By customizing camera parameters to force adaptation to the "Technical Specifications for Land Change Survey", manual intervention is reduced, field evidence collection efficiency is improved by 40%, and the first-time data qualification rate reaches over 98%.

[0018] II. Data Credibility and Tamper-Proof Guarantee: Integrating the SM2 / SM3 national cryptographic algorithms, the system encrypts and verifies the integrity of photo metadata (SM3) and signs it (SM2), ensuring data confidentiality, secure storage and transmission, and traceability of origin, with a tamper detection rate of 99.99%. It enables network transmission of evidentiary document information, eliminating the need for manual export and import of evidentiary documents and effectively improving the efficiency of evidence collection.

[0019] III. Enhanced full-chain traceability: Watermark overlay (shooting direction angle, shooting angle, longitude of camera positioning module, longitude of camera positioning module) and geographic metadata (longitude, latitude, azimuth, relative altitude, original resolution width-height, 35mm equivalent focal length, shooting date, photographer (base64 encoded), certificate code, absolute altitude, roll angle, pitch angle) are written into the EXIF ​​of the photo, supporting data traceability to the user level (digital certificate), ensuring that the information in the evidence documents meets the requirements of the "Technical Specifications for Land Change Survey".

[0020] IV. Multi-technology integration and innovation: The first-ever combination of "positioning + small map navigation + real-time direction angle correction" function completes the direction angle calculation of photos, reducing the positioning time of field personnel by 70%.

[0021] V. Standardization and Scalability Compatibility: The modular design of the SDK supports rapid integration with land change survey business and other natural resource-related businesses with similar evidentiary data requirements. The data encapsulation format (.GDB) is compatible with the 2000 National Geodetic Coordinate System, providing a unified interface for cross-departmental (land / forestry) collaboration and enabling the reusability of field survey evidence results. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating the method for encrypting and preventing tampering of field evidence documents in land change survey technology provided by this invention.

[0024] Figure 2 This is a schematic diagram of location and map integration and watermark embedding.

[0025] Figure 3 This is a flowchart of the method for encrypting and preventing tampering of field evidence documents in the land change survey technology provided by the present invention. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] Please see Figures 1 to 3 This invention provides a method for encrypting and preventing tampering of field evidence documents related to land change surveys, comprising the following steps;

[0028] S1 uses authorization and authentication to initialize the camera, and allows users to customize camera module parameters and buttons via the mobile app.

[0029] In this embodiment of the invention, authorization authentication is used: a standardized API interface is provided, supporting the HTTPS protocol and RESTful design specifications, allowing third-party applications to call and complete the authorization authentication using the development toolkit;

[0030] Initialize the camera and customize the camera module parameters and buttons via the mobile app. Force the Android system camera to set the resolution, focal length, and exposure parameters and disable third-party filter functions. Take photos that comply with the "Technical Specifications for Land Change Survey" via the customized camera module on the mobile app.

[0031] The camera module's dedicated UI includes an eagle-eye map, flash switch, photo button, video button, and front / rear camera switching button.

[0032] The use of authorization and authentication includes the following steps:

[0033] 1. Authorization Key Generation: A unique authorization key is generated according to established rules. The key is 64 bits long and its format combines letters, numbers and special characters. It is then distributed to the corresponding user through secure means such as encrypted email to ensure that it is not stolen or tampered with during transmission.

[0034] II. Server-side preparation: Establish a dedicated database on the server side to store authorization keys and detailed information of the user, such as user name, contact information, and usage scenario;

[0035] 3. Application Launch Authentication: The Android system embeds authentication logic in the onCreate method of the Application class of an application. When the application starts, it sends an authentication request to the server and passes the obtained authorization key to the server;

[0036] IV. Application Feedback: Based on the authentication result returned by the server, if the authentication is successful, the application will load normally and use the received configuration information to perform subsequent operations; if the authentication fails, the user will be prompted with a friendly message explaining the reason for the failure, such as "Invalid authorization key, please contact the administrator," guiding the user to take appropriate measures to resolve the issue.

[0037] V. Regular checks: The application regularly checks the status of the authorization key during operation to ensure that the key does not encounter problems even during use;

[0038] VI. Communication Encryption: The entire authentication process and subsequent communication between the application and the server are encrypted using SSL / TLS to further ensure the security of data transmission and prevent critical data such as authorization keys and configuration information from being stolen or tampered with during transmission.

[0039] Initializing the camera and customizing camera module parameters and buttons via the mobile device includes the following steps:

[0040] 1. Camera initialization: After successfully obtaining camera permissions, the camera initialization operation is carried out using libraries such as CameraX, based on the Android mobile system API.

[0041] II. Photo Parameter Settings: By setting the relevant properties of the CameraX library, including options for multiple resolutions such as 1080P and 2K, and by utilizing the system API in close cooperation with the CameraX library, a frame rate of up to 240fps can be achieved.

[0042] III. Customized UI, including Eagle Eye Map, flash switch, video recording, photo taking, start photo and video recording buttons, front and rear camera switching buttons, etc. (Design drawings attached) Figure 2 .

[0043] S2 acquires the device's posture information when the investigator takes a photo, and combines it with the device's geographical location information to calculate the photo's orientation angle using trigonometric functions and vector operations.

[0044] In this embodiment of the invention, by acquiring the attitude information of the device when the investigator takes the photo, including roll angle, pitch angle, and yaw angle, and combining it with the device's geographical location information, the orientation angle of the photo is calculated using mathematical tools such as trigonometric functions and vector operations. Specifically, using the device's gyroscope's true north direction as a reference, assuming the coordinates of the investigator's location are (lat1, lon1) and the coordinates of the target point are (lat2, lon2), the vector connecting the two points is first calculated. Then, based on the coordinate representation of the vector, the angle θ between the vector and the true north direction is calculated using the arctangent function, with the formula:

[0045]

[0046] in, .

[0047] In the actual calculation process, factors such as coordinate system transformation and the range of angle values ​​also need to be considered to ensure that the calculated direction angles are accurate and meet the actual needs of the land change survey. The coordinate system adopted is the "2000 National Geodetic Coordinate System", the elevation datum is the "1985 National Elevation Datum", and the projection method is the Gauss-Kruger projection.

[0048] S3 integrates the location map into the captured photo and adds a watermark to the captured photo;

[0049] In this embodiment of the invention, combining positioning functionality with a map enables real-time location display, trajectory recording, and target point annotation, improving the efficiency and accuracy of fieldwork. Using the TencentLocationSDK-v7.5.4.10 framework, the positioning map is integrated into the photo view, allowing for a clear view of the current location and its relationship to map features during evidence photography. This facilitates accurate location confirmation, enabling the association of field evidence photos, videos, and text records with their location on the map, preventing data errors due to location discrepancies, and ensuring data integrity. The design is as follows... Figure 2 :

[0050] The watermarking includes the shooting time, shooting direction angle, shooting angle, longitude of the camera positioning module, and longitude of the camera positioning module, which are directly superimposed on the original image in the form of multi-line text. The watermarking function is implemented by drawing the Bitmap using Canvas.

[0051] S4 acquires high-precision latitude and longitude coordinates and altitude data when the photo is taken, writes the required geographic metadata into the image file of the photo by calling the Android system, and then encodes and encapsulates the image file according to the standard format;

[0052] In this embodiment of the invention, geographic metadata is written into the EXIF ​​data of the photo, following the 2.30 standard (CIPA DC-008-2012). High-precision latitude and longitude coordinates and altitude data at the time the photo was taken are obtained from the phone's positioning module. Then, this data is encoded and encapsulated according to the EXIF ​​standard format by calling the Android system API. The EXIF ​​data of the photo should ideally include longitude, latitude, azimuth, relative altitude, original resolution width-height, 35mm equivalent focal length, shooting date, photographer (base64 encoded), certificate code, absolute altitude, roll angle, and pitch angle. The corresponding relationships are shown in the table below:

[0053]

[0054] Includes the following steps:

[0055] 1. Reading the raw image file: First, the raw image file needs to be read and its existing EXIF ​​data (if any) parsed out. Different programming languages ​​and platforms provide corresponding libraries or APIs to read image files and extract EXIF ​​data.

[0056] 2. Modify or Add EXIF ​​Data: Modify or add new EXIF ​​tags to the extracted EXIF ​​data as needed. This may involve modifying specific tags, such as changing the shooting time, adding user-defined annotations, or inserting GPS location information.

[0057] 3. Write the modified EXIF ​​data back to the file: Re-encode the modified or added EXIF ​​data and write it back to the image file. It is important to ensure the integrity of the image file is maintained during the write-back process, without affecting the image's pixel data and other non-EXIF metadata.

[0058] S5 performs hash calculations on the captured photos and survey data to obtain a data digest, generates a unique and tamper-proof request code, and transmits it to the server for digital signature.

[0059] In this embodiment of the invention, SM3 (cryptographic hash algorithm) is used to perform hash calculations on the captured photos and survey data to obtain a unique identifier request code (this code is used to generate a verification code after digital signature by the server). The core logical steps of the complete algorithm implementation are as follows:

[0060] I. Photo Summary Data Extraction

[0061] Reading photo byte streams: Reading photo files from storage media (such as a file system) and converting them into byte streams to ensure data integrity.

[0062] SM3 Algorithm Operation: According to the SM3 algorithm standard, the photo byte stream is grouped, padded, and iteratively operated to generate photo summary data.

[0063] II. EXIF ​​Data Parsing and Processing

[0064] Parse EXIF ​​data: Extract EXIF ​​data from photo files based on the photo format (such as the storage structure of EXIF ​​data in JPEG format).

[0065] Data format conversion: The parsed EXIF ​​data is organized into byte format for subsequent concatenation with the summary data.

[0066] III. Data Concatenation and Verification Code Generation

[0067] Data stitching: stitching photo summary data and processed EXIF ​​data into a new data block in a specific order (e.g., first summary data then EXIF ​​data).

[0068] SM3 operation again: The concatenated data block is used as input, and the SM3 algorithm is used again to generate a request code, which is then transmitted to the server for digital signature using the SM2 algorithm to generate the final verification code.

[0069] IV. Verification Process

[0070] Data Reception: The receiver obtains the photo and its corresponding verification code, decrypts it using the SM2 algorithm to obtain the request code, and recalculates the request code using the photo and geographic metadata. The receiver then extracts the photo summary data and EXIF ​​data using the same process, concatenates them, and recalculates the request code. Verification Code Comparison: The recalculated request code is compared with the received request code. If they match, the photo data is complete and authentic.

[0071] The present invention also provides a software development kit (SDK), including an authorization and authentication module, a camera parameter configuration module, a metadata processing module, and an encryption module;

[0072] The authorization and authentication module is used to verify the legitimacy of the device and the user;

[0073] The camera parameter configuration module dynamically sets camera parameters based on the land change survey specifications.

[0074] The metadata processing module is used to perform orientation angle calculation, EXIF ​​geographic information writing, and watermark overlay.

[0075] The encryption module, based on the SM2 and SM3 national cryptographic algorithms, performs digest extraction, digest signing, and verification on the captured photos and survey data;

[0076] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for encrypting and preventing tampering of field evidence documents in land change survey technology, characterized in that: Includes the following steps; Use authorization and authentication to initialize the camera, and customize the camera module parameters and buttons through the mobile app; The orientation information of the equipment when the investigators take photos is obtained, and combined with the geographical location information of the equipment, the orientation angle of the photos is calculated using trigonometric functions and vector operations. The location map is integrated into the captured photos, and the captured photos are watermarked. The system acquires high-precision latitude and longitude coordinates and altitude data when the photo is taken, writes the required geographic metadata into the image file of the photo by calling the Android system, and then encodes and encapsulates the image file according to a standard format. The captured photos and survey data are hashed to obtain a data digest, a unique and tamper-proof request code is generated, and transmitted to the server for digital signature.

2. The method for encrypting and preventing tampering of field evidence documents in land change survey technology as described in claim 1, characterized in that... ； The camera module's dedicated UI includes an eagle-eye map, flash switch, photo button, video button, and front / rear camera switching button.

3. The method for encrypting and preventing tampering of field evidence documents in land change survey technology as described in claim 1, characterized in that... ； The attitude information includes the heading angle, roll angle, and pitch angle.

4. The method for encrypting and preventing tampering of field evidence documents in land change survey technology as described in claim 1, characterized in that; The watermarking includes the shooting time, shooting direction angle, shooting angle, longitude of the camera positioning module, and longitude of the camera positioning module, which are directly superimposed on the original image in the form of multi-line text.

5. The method for encrypting and preventing tampering of field evidence documents related to land change survey technology as described in claim 1. Its characteristics are: The image file should contain longitude, latitude, azimuth, relative altitude, original resolution width-height, 35mm equivalent focal length, shooting date, photographer, certificate code, absolute altitude, roll angle, and pitch angle.

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