Hid protocol and image codec based driverless isolated transmission method and system

Abstract

The application relates to the technical field of information transmission, in particular to an efficient driver-free isolation transmission method and system based on a HID protocol and image coding and decoding, a sending end on an external network equipment compresses, divides and encodes a to-be-transmitted file to generate an image sequence, and dynamically loads the images in sequence; an HID equipment collects images through a camera and extracts image data for transmission; a receiving end on an internal network equipment acquires HID equipment data through the HID protocol, and decodes, restores and decompresses the data, so that the problem of safe data transmission under network isolation is solved.

Description

Technical Field

[0001] This invention relates to the field of information transmission technology, and in particular to a driverless isolated transmission method and system based on HID (Human Interface Device) protocol and image encoding and decoding. Background Technology

[0002] With the continuous development of information technology and the increasing popularity of information applications, network applications are becoming more and more frequent. Enterprises and institutions exchange a large amount of information between the Internet and their intranets to improve efficiency. However, most enterprises and institutions have high requirements for the confidentiality of internal information. Once sensitive information is stolen, it will have serious consequences. How to further enhance the security and efficiency of information exchange has become a hot research topic. The Internet is a world-class network, but it is also a network that is difficult to control in terms of security. During its application, problems such as network attacks, virus intrusions, and information leaks caused by unauthorized access are emerging one after another, posing a serious threat to data security.

[0003] Currently, the most effective way to ensure security and confidentiality when transmitting data between an intranet and the internet is physical isolation. Physical isolation means that the internal LAN never has a direct physical connection to the internet, thus truly protecting network security. While this method improves security, it also introduces problems with data exchange. How to effectively exchange information between the intranet and the internet is one of the most important issues facing isolated transmission. Common methods currently include unidirectional optical gates based on fiber optics and optical disc transfer devices based on disposable optical discs. However, these methods suffer from the risks of physical connections, resource waste, and low efficiency.

[0004] To address the two scenarios mentioned above, a new method based on QR code display and camera capture / reconstruction has been developed for isolated unidirectional transmission. This method resolves the potential risks associated with physical connections in the transmission path, but it still suffers from low efficiency and unstable transmission. Furthermore, this method requires a camera to be installed on the receiving computer, which may violate security regulations and may also lead to issues such as needing to install drivers for the camera to function properly and efficiently.

[0005] Therefore, researching a more effective and efficient method and system to achieve secure data transmission under conditions of complete network isolation is a very meaningful task. Summary of the Invention

[0006] To address the above problems, the present invention provides the following solution:

[0007] A driverless isolated transmission method based on the HID protocol and image encoding / decoding is proposed. The sending end on the external network device compresses, segments, and encodes the file to be transmitted to generate an image sequence, and dynamically loads the ordered images. The HID device captures images through a camera and extracts the image data for transmission. The receiving end on the internal network device obtains the HID device data through the HID protocol, and decodes, restores, and decompresses the data, thus solving the problem of secure data transmission under network isolation. Specifically, it consists of the following steps:

[0008] S1, construct a driverless isolated transmission system based on HID protocol and image encoding / decoding, and complete initialization.

[0009] S1.1 Construct a driverless isolated transmission system based on the HID protocol and image encoding / decoding. This system consists of three parts: a sending end running on an external network device; an HID device connecting to an internal network device; and a receiving end running on the internal network device. The sending end comprises a file acquisition module, a file preprocessing module, a data encoding module, an image encoding module, and an image dynamic loading module; the HID device comprises an image acquisition module, an image decoding module, and an HID data transmission module; and the receiving end comprises an HID data receiving module, a data decoding and reconstruction module, and a target file generation module.

[0010] S1.2 Initialize the receiver;

[0011] S1.3 Initialize the HID device and set the camera's capture resolution and capture speed;

[0012] S1.4 Initialize the sending end, set the data fragment size δ and fragment redundancy λ, where δ and λ are positive numbers for use in S2.3;

[0013] S2, the sending end converts the file into numerous images and displays them dynamically on the screen. The method is as follows:

[0014] The S2.1 file acquisition module acquires the original file to be sent input by the user: if there is an original file to be sent, it is sent to the file preprocessing module and then transferred to S2.2; if not, it is transferred to S2.1 to continue waiting for user input.

[0015] The S2.2 file preprocessing module receives the original file to be sent from the file acquisition module, uses fast real-time compression algorithms (such as Zstandard compression algorithm) to process the original file to be sent to generate intermediate data to be encoded, and sends the intermediate data to be encoded to the data encoding module.

[0016] S2.3 The data encoding module receives the intermediate data to be encoded from the file preprocessing module, and encodes the intermediate data to be encoded with a total size of k data slices using an erasure code algorithm (such as Fountain Code algorithm), generating a data slice group containing N data slices, where N>>k = S / δ; the intermediate data to be encoded can be recovered by decoding any m of these data slices, and then the data slice group is sent to the image encoding module; where m =⌈ (1+ε) k⌉, ⌈ ⌉ represents the rounding operation, and k, m, and N are all positive integers and k<m<N; ε is a positive number that makes m slightly larger than k, determined by the erasure code algorithm (such as Fountain Code algorithm); the data slice size δ is determined by the acquisition resolution of the camera of the HID device and the image encoding and decoding algorithm; the slice redundancy λ is determined by the erasure code algorithm for encoding the intermediate data in S2.3, the image display switching speed in S2.5, and the camera acquisition speed of the HID device; N =(1+λ) m, to provide redundancy for camera acquisition errors; (if the λ value is too small, after all the images in S2.5 are displayed once, the HID device may not have collected enough slices, and it is necessary to continue to collect the loop-displayed images in S2.5, then many duplicate images will be encountered and the transmission efficiency will be reduced; if the λ value is too large, the encoding time of S2.3 and S2.4 will become longer, and the overall transmission speed will also be reduced).

[0017] S2.4 The image encoding module receives the data slice group from the data encoding module, and encodes each data slice of the data slice group one by one to generate an image. The method is as follows:

[0018] S2.4.1 Assume that there are N data slices in the data slice group received from the data encoding module, and let the data slice serial number be n, where n = 1, 2, ···, N;

[0019] S2.4.2 Use an image encoding technology (such as HCCB proposed by Microsoft, QRCode proposed by Denso Corporation of Japan, etc.) to encode the nth data slice to generate an encoded image, and send it to the image dynamic loading module;

[0020] S2.4.3 Let the data slice serial number n=n + 1, until n=N to complete the encoding of all data slices, and then go to S2.5;

[0021] S2.5 The image dynamic loading module receives the encoded images from the image encoding module, and uses the system-built timing function (such as the QTimer function in QT on the Windows system) to sequentially loop-display all the encoded images at a speed not exceeding the monitor refresh frequency;

[0022] S3. The HID device acquires and decodes images and transmits data through HID messages. The method is as follows:

[0023] S3.1 The image acquisition module reads the image displayed by the image dynamic loading module through the camera of the HID device. If an image is read, it is sent to the image decoding module and then proceeds to S3.2; if no image is read, it returns to S3.1 to continue the loop and wait to read.

[0024] The S3.2 image decoding module receives images from the image acquisition module, extracts data fragments from the images using image encoding technologies (such as HCCB, QRCode, etc.), and sends them to the HID data transmission module.

[0025] The S3.3 HID data transmission module receives data fragments from the image decoding module, encapsulates the data fragments according to the HID message format to generate HID data messages, and then sends the HID data messages to the receiving end running on the intranet device through the HID transmission protocol.

[0026] S4, the receiver continuously waits to receive HID data packets and generates the target file, using the following method:

[0027] The S4.1 HID data receiving module receives HID data packets and parses them to obtain data fragments. The method is as follows:

[0028] S4.1.1 The HID data receiving module at the receiving end receives HID data packets from the HID data sending module of the HID device;

[0029] S4.1.2 If a HID data packet is received, proceed to S4.1.3; if no HID data packet is received, proceed to S4.1.1 to continue waiting for a HID data packet.

[0030] S4.1.3 The HID data receiving module parses the HID data packet, extracts data fragments from it, and sends them to the data decoding and reassembly module;

[0031] The S4.2 data decoding and reassembly module receives data fragments from the HID data receiving module and performs decoding and reassembly. The method is as follows:

[0032] S4.2.1 Check if the data fragment already exists in the fragment buffer. If it exists, proceed to S4.1.1; otherwise, proceed to S4.2.2.

[0033] S4.2.2 Place the received data fragments into the data fragment buffer and increment the number of data fragments n stored in the data fragment buffer by 1;

[0034] S4.2.3 Determine if data can be reassembled, i.e., whether n is greater than or equal to m. If yes, it means that the number of data fragments required for data decoding and reassembly has been met, and proceed to S4.2.4; otherwise, proceed to S4.1.1.

[0035] S4.2.4 Merge the received n data fragments into complete intermediate data to be encoded using an erasure code algorithm (such as the fountain code algorithm), and send it to the target file generation module, then proceed to S4.3;

[0036] The S4.3 target file generation module receives the complete intermediate data to be encoded from the data decoding and reassembly module, processes it using a reverse algorithm (such as the Zstandard decompression algorithm) corresponding to the file preprocessing module at the sending end, such as fast real-time decompression, and finally generates the original file, completing a transmission from the external network device to the internal network device.

[0037] This invention also provides a driverless isolated transmission system based on the HID protocol and image encoding and decoding. The system comprises three parts: a transmitting end running on an external network device; an HID device connected to an internal network device; and a receiving end running on an internal network device.

[0038] The sending end consists of a file acquisition module, a file preprocessing module, a data encoding module, an image encoding module, and an image dynamic loading module. The file acquisition module acquires the file input by the user on the external network device (i.e., the original file to be sent) and sends a file processing request (the parameter being the original file to be sent) to the file preprocessing module. The file preprocessing module receives the file processing request (the parameter being the original file to be sent) from the file acquisition module, processes the original file using algorithms such as fast real-time compression (e.g., Zstandard compression), generates intermediate data to be encoded, and sends a data encoding request (the parameter being the intermediate data to be encoded) to the data encoding module. The data encoding module receives the data encoding request (the parameter being the intermediate data to be encoded) from the file preprocessing module and processes the intermediate data to be encoded... The data is encoded into a group of data fragments with a predetermined number of fragments using an erasure code algorithm (such as fountain code). Then, an image encoding request (with the data fragment group as the parameter) is sent to the image encoding module. The image encoding module receives the image encoding request (with the data fragment group as the parameter) from the data encoding module, obtains the data fragment group to be encoded, and uses image encoding and decoding technologies (such as HCCB proposed by Microsoft, QRCode proposed by Denso Corporation of Japan) to encode each fragment in the data fragment group to be encoded, generating an encoded image. This image is then sent to the image dynamic loading module as a display request (with the encoded image as the parameter). The image dynamic loading module receives the display request (with the encoded image as the parameter) from the image encoding module and loads and displays all the encoded images in a loop for the HID device's camera to capture.

[0039] HID devices consist of a camera, an image acquisition module, an image decoding module, and an HID data transmission module. The image acquisition module acquires images that are dynamically displayed on the image loading module through the camera and sends a decoding request (the parameter being the acquired image) to the image decoding module. The image decoding module receives the decoding request (the parameter being the acquired image) from the image acquisition module, extracts data fragments from the acquired image using image encoding and decoding technologies (such as HCCB, QRCode, etc.), and then sends a transmission request (the parameter being the data fragment) to the HID data transmission module. The HID data transmission module receives the transmission request (the parameter being the data fragment) from the image decoding module, encapsulates the data fragments into HID data packets, and sends them to the receiving end running on the intranet device.

[0040] The receiving end consists of an HID data receiving module, a data decoding and reassembly module, and a target file generation module. The HID data receiving module on the intranet device reads the HID data packets transmitted by the HID data sending module on the HID device and extracts data fragments. It then sends a decoding request (with the data fragment as the parameter) to the data decoding and reassembly module. The data decoding and reassembly module receives the decoding request (with the data fragment as the parameter) from the HID data receiving module, places the data fragments into a fragment buffer, and if the number of data fragments in the fragment buffer meets the data reassembly requirements, merges the data fragments into complete intermediate data to be encoded and sends a file generation request (with the intermediate data to be encoded) to the target file generation module. The target file generation module receives the file generation request (with the intermediate data to be encoded) from the data decoding and reassembly module, processes the received intermediate data to be encoded using a reverse algorithm (such as the Zstandard decompression algorithm) corresponding to the file preprocessing module at the sending end, and obtains the original file, thus completing the target file generation task.

[0041] Furthermore, the HID device is an HID device made using a high-performance smart device, such as a Raspberry Pi. HID devices using low-end embedded chips, such as barcode scanners, keyboards, and mice, are limited by their low performance, allowing only low-speed and simple image encoding, and cannot achieve efficient isolation of transmission destinations. In contrast, HID devices made using high-performance and low-cost smart devices can effectively combine factors such as display refresh rate, camera capture frequency and resolution, and device encoding / decoding speed to achieve efficient transmission.

[0042] The following technical effects can be achieved by using this invention:

[0043] 1. This invention uses erasure codes to encode the file to be sent into a fragment set. The number of fragments N in this fragment set is greater than the number of fragments m required to recover the encoded file. As long as any m fragments are received, the original file can be synthesized, thereby greatly reducing the number of images to be acquired and decoded for data recovery and improving the stability and speed of data transmission.

[0044] 2. This invention uses images as the carrier of data during data transmission. The sending end encodes and decodes data fragments using image encoding and decoding technology, and achieves unidirectional, feedback-free data transmission with the receiving end through HID devices, ensuring the efficiency and security of the data transmission process.

[0045] 3. This invention uses the HID protocol as the communication protocol used by the receiving end for final reception. While ensuring physical isolation from the sending end, it eliminates the need to install a camera on the receiving end device, avoiding security risks caused by cameras and the inconvenience of installing drivers, thus achieving safe and driverless operation.

[0046] This invention can be applied to the field of information transmission, such as internal and external network information exchange systems, and data exchange systems under physical isolation. Attached Figure Description

[0047] Figure 1 This is the overall architecture diagram of the driverless isolated transmission system based on HID protocol and image encoding and decoding technology constructed in the first step of this invention;

[0048] Figure 2 This is a flowchart of the driverless isolation transmission method based on HID protocol and image encoding and decoding technology of the present invention.

[0049] Figure 3 This is a logical structure diagram of the driverless isolation transmission method based on HID protocol and image encoding and decoding technology of the present invention. Detailed Implementation

[0050] Figure 1 This is the overall structure diagram of the driverless isolated transmission system based on HID protocol and image encoding / decoding technology constructed in the first step of this invention. The system mainly consists of three parts: a transmitting end running on an external network device; a receiving end running on an internal network device; and an HID device connected to the internal network device.

[0051] Figure 2 This is the overall flowchart of the present invention. The present invention includes the following steps:

[0052] S1, construct a driverless isolated transmission system based on HID protocol and image encoding and decoding technology; the system consists of three parts: first, a transmitting end running on external network devices; second, an HID device connecting internal network devices; and third, a receiving end running on internal network devices.

[0053] S2, the sending end converts the file into numerous images and displays them dynamically on the screen;

[0054] S3, HID devices acquire and decode images and transmit data via HID messages;

[0055] S4, the receiving end continuously waits to receive HID data packets and generates the target file.

[0056] The specific working process of this method in practical applications is shown in the following example:

[0057] To implement a driverless, isolated transmission system for HID protocol and image encoding / decoding, this example uses a 1600-pixel camera. The data acquisition speed is 60fps, the preprocessing operation used is a no-operation, the erasure code algorithm used is fountain code, and the hardware parameters of the external network PC device, HID device (Raspberry Pi), and internal network PC device are shown in the table below:

[0058]

[0059] (1) Use the sending end on the external network device to select the file to be transmitted. The sending end will preprocess, fragment, encode, generate an image and load it dynamically.

[0060] If the selected file format is Word and the size is S=550KB, the selected file is first preprocessed (in this example, the preprocessing operation is empty) to obtain intermediate data. Then, the fountain code algorithm is used to encode the intermediate data into data fragments.

[0061] Based on the camera's performance, the image resolution is determined to be 844. 844. Based on the image encoding algorithm, the data fragment size at this image resolution is δ=4.8KB, and the fragment redundancy is set to λ=0.5. Furthermore, based on the fountain code algorithm, ε=0.05 is determined, resulting in any... If a data fragment of size S can be recovered, then when encoding the intermediate data of size S, the generated data fragments are determined. indivual.

[0062] A complete data sharding format is shown in the table below:

[0063]

[0064] If the data segment with the sequence number id1 is selected, image encoding technology is used to encode it to generate a QR code image.

[0065] (2) The camera on the HID device continuously captures the images displayed on the sending end of the external network device, and then decodes the images and encapsulates them into HID data packets for transmission.

[0066] For example, after a camera reads a frame of image, it decodes it using image decoding technology to obtain data fragments. These data fragments are then encapsulated into HID data packets according to the HID packet format. Finally, the HID data packets are transmitted to the receiving end of the intranet device via the HID transmission protocol. The packet format is shown in the table below:

[0067]

[0068] (3) The receiving end on the intranet device continuously receives HID data packets transmitted by the HID device, and parses, fragments and reassembles the data packets to generate target files.

[0069] First, the received HID data packet is parsed to obtain data fragments, which are then stored in a data fragment cache pool. A condition is satisfied when the total number of data fragments n stored in the data fragment cache pool is greater than or equal to any m data fragments required to recover intermediate data. When the conditions for reassembly and recovery are met, all received data fragments are decoded and reassembled to obtain intermediate data, and finally the intermediate data is restored to the target file.

[0070] (4) Based on the above steps, it can be seen that with a camera frame rate of 60fps and each image carrying 4.8KB of effective data, the theoretical maximum transmission speed can be calculated. KB / s. However, due to limitations such as the device's hardware processing power, the stable transfer speed in this example is approximately 75KB / s.

Claims

1. A driverless isolated transmission method based on HID protocol and image codec, characterized in that, This method consists of the following steps: S1, Construct a driverless isolated transmission system based on HID protocol and image encoding / decoding, and complete initialization; S1.1 Construct a driverless isolated transmission system based on the HID protocol and image encoding / decoding. This system consists of three parts: a sending end running on an external network device; an HID device connecting to an internal network device; and a receiving end running on an internal network device. The sending end consists of a file acquisition module, a file preprocessing module, a data encoding module, an image encoding module, and an image dynamic loading module. The HID device consists of a camera, an image acquisition module, an image decoding module, and an HID data transmission module. The receiving end consists of an HID data receiving module, a data decoding and reconstruction module, and a target file generation module. S1.2 Initialize the receiver; S1.3 Initialize the HID device and set the camera's capture resolution and capture speed; S1.4 Initialize the sending end, set the data fragment size δ and fragment redundancy λ, where δ and λ are positive numbers for use in S2.3; S2, the sending end converts the file into numerous images and displays them dynamically on the screen. The method is as follows: The S2.1 file acquisition module acquires the original file to be sent input by the user: if there is an original file to be sent, it is sent to the file preprocessing module and then transferred to S2.2; if not, it is transferred to S2.1 to continue waiting for user input. The S2.2 file preprocessing module receives the original file to be sent from the file acquisition module, uses algorithms such as fast real-time compression to process the original file to be sent to generate intermediate data to be encoded, and sends the intermediate data to be encoded to the data encoding module. S2.3 The data encoding module receives the intermediate data to be encoded from the file preprocessing module, and encodes the intermediate data to be encoded with a total size of k data shards using an erasure code algorithm to generate a data shard group containing N data shards, where N >> k = S / δ; the intermediate data to be encoded can be recovered by decoding any m of the data shards, and then the data shard group is sent to the image encoding module; where m = ⌈(1 + ε) k⌉, ⌈ ⌉ represents the rounding operation, and k, m, and N are all positive integers and k < m < N; S is the size of the intermediate data; ε is a positive number such that m is slightly larger than k, which is determined by the erasure code algorithm; the data shard size δ is determined by the camera acquisition resolution of the HID device and the image encoding and decoding algorithm; the shard redundancy λ is determined by the erasure code algorithm for encoding the intermediate data in S2.3, the image display switching speed in S2.5, and the camera acquisition speed of the HID device; N = (1 + λ) m, to provide redundancy for camera acquisition errors; S2.4 The image encoding module receives data fragment groups from the data encoding module, and encodes each data fragment in the data fragment group one by one to generate an image. The method is as follows: S2.4.1 Let there be N data fragments in the data fragment group received from the data encoding module, and let the data fragment number be n, n=1, 2, ..., N; S2.4.2 Use image encoding technology to encode the nth data segment to generate an encoded image, and send it to the image dynamic loading module; S2.4.3 Set the data fragment sequence number n = n + 1 until n = N to complete the encoding of all data fragments, then go to S2.5; The S2.5 image dynamic loading module receives encoded images from the image encoding module and uses the system's built-in timing function to sequentially display all encoded images in a loop at a speed not exceeding the display refresh rate. S3, the HID device acquires and decodes images and transmits data via HID messages, using the following method: S3.1 The image acquisition module reads the image displayed by the image dynamic loading module through the camera of the HID device. If an image is read, it is sent to the image decoding module and then proceeds to S3.2; if no image is read, it returns to S3.1 to continue the loop and wait to read. The S3.2 image decoding module receives images from the image acquisition module, uses image encoding technology to extract data fragments from the images, and sends them to the HID data transmission module; The S3.3 HID data transmission module receives data fragments from the image decoding module, encapsulates the data fragments according to the HID message format to generate HID data messages, and then sends the HID data messages to the receiving end running on the intranet device through the HID transmission protocol. S4, the receiver continuously waits to receive HID data packets and generates the target file, using the following method: The S4.1 HID data receiving module receives HID data packets and parses them to obtain data fragments. The method is as follows: S4.1.1 The HID data receiving module at the receiving end receives HID data packets from the HID data sending module of the HID device; S4.1.2 If a HID data packet is received, proceed to S4.1.3; if no HID data packet is received, proceed to S4.1.1 to continue waiting for a HID data packet. S4.1.3 The HID data receiving module parses the HID data packet, extracts data fragments from it, and sends them to the data decoding and reassembly module; The S4.2 data decoding and reassembly module receives data fragments from the HID data receiving module and performs decoding and reassembly. The method is as follows: S4.2.1 Check if the data fragment already exists in the fragment buffer. If it exists, proceed to S4.1.1; otherwise, proceed to S4.2.

2. S4.2.2 Place the received data fragments into the data fragment buffer and increment the number of data fragments n stored in the data fragment buffer by 1; S4.2.3 Determine if data can be reassembled, i.e., whether n is greater than or equal to m. If yes, it means that the number of data fragments required for data decoding and reassembly has been met, and proceed to S4.2.4; otherwise, proceed to S4.1.

1. S4.2.4 Merge the received n data fragments into complete intermediate data to be encoded using the erasure code algorithm, and send it to the target file generation module, then proceed to S4.3; The S4.3 target file generation module receives the complete intermediate data to be encoded from the data decoding and reconstruction module, processes it using the reverse algorithm corresponding to the file preprocessing module at the sending end, such as fast real-time decompression, and finally generates the original file, completing a transmission from the external network device to the internal network device. Using the HID protocol as the communication protocol used by the receiving end eliminates the need to install a camera on the receiving device.

2. A driverless isolated transmission method based on HID protocol and image encoding / decoding according to claim 1, characterized in that: In S2.2, the fast real-time compression algorithm used is the Zstandard compression algorithm.

3. A driverless isolated transmission method based on HID protocol and image encoding / decoding according to claim 1, characterized in that: In S2.3 and S4.2.4, the erasure code algorithm used is the fountain code algorithm.

4. A driverless isolated transmission method based on HID protocol and image encoding / decoding according to claim 1, characterized in that: The image encoding technologies used in S2.4.2 and S3.2 are HCCB and QRCode.

5. A driverless isolated transmission method based on HID protocol and image encoding / decoding according to claim 1, characterized in that: In S2.5, the built-in timer function used is the QTimer function in QT on Windows systems.

6. A driverless isolated transmission method based on HID protocol and image encoding / decoding according to claim 1, characterized in that: In S4.3, the fast real-time decompression algorithm used is the Zstandard decompression algorithm.

7. A driverless isolated transmission system based on HID protocol and image encoding / decoding, characterized in that: The system consists of three parts: first, a transmitter running on external network devices; second, an HID device connecting to internal network devices; Thirdly, the receiving end running on intranet devices; The sending end consists of a file acquisition module, a file preprocessing module, a data encoding module, an image encoding module, and an image dynamic loading module; the file acquisition module is used to acquire the file input by the user in the external network device and send the file processing request to the file preprocessing module; The file preprocessing module receives a file processing request from the file acquisition module, uses a fast real-time compression algorithm to process the original file to be sent, generates intermediate data to be encoded, and sends a data encoding request to the data encoding module. The data encoding module receives the data encoding request from the file preprocessing module, encodes the intermediate data to be encoded into a data fragment group with a determined number of fragments using an erasure code algorithm, and then sends an image encoding request to the image encoding module. The image encoding module receives the image encoding request from the data encoding module, obtains the data fragment group to be encoded, uses image encoding and decoding technology to encode each fragment in the data fragment group to be encoded, generates an encoded image, and sends a display request to the image dynamic loading module. The image dynamic loading module receives display requests from the image encoding module and loads all encoded images in a loop for display by the camera of the HID device. HID devices consist of a camera, an image acquisition module, an image decoding module, and an HID data transmission module. The image acquisition module captures images that are dynamically displayed on the image loading module through the camera and sends a decoding request to the image decoding module. The image decoding module receives the decoding request from the image acquisition module, extracts data fragments from the acquired images using image encoding and decoding technology, and then sends a transmission request to the HID data transmission module. The HID data transmission module receives the transmission request from the image decoding module, encapsulates the data fragments into HID data packets, and sends them to the receiving end running on the intranet device. The receiving end consists of an HID data receiving module, a data decoding and reassembly module, and a target file generation module. The HID data receiving module on the intranet device reads the HID data packets transmitted by the HID data sending module on the HID device and extracts the data fragments, and sends a decoding request to the data decoding and reassembly module. The data decoding and reassembly module receives a decoding request from the HID data receiving module, puts the data fragments into the fragment buffer, and if the number of data fragments in the fragment buffer meets the data reassembly requirements, it merges the data fragments into complete intermediate data to be encoded and sends a file generation request to the target file generation module. The target file generation module receives the file generation request from the data decoding and reconstruction module, processes the received intermediate data to be encoded through a reverse algorithm corresponding to the file preprocessing module at the sending end, such as fast real-time decompression, to obtain the original file and complete the target file generation task. Using the HID protocol as the communication protocol used by the receiving end eliminates the need to install a camera on the receiving device.

8. A driverless isolated transmission system based on HID protocol and image encoding / decoding according to claim 7, characterized in that: The HID device is a Raspberry Pi.

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