A wireless image transmission method based on a private Wi-Fi network secure connection

Abstract

The application discloses a wireless image transmission method based on a private Wi-Fi network security connection, and relates to the technical field of wireless communication. First, an original Beacon frame is generated and encrypted, the encrypted Beacon frame is encapsulated into an access point Action frame and an identifier is added to obtain a first Action frame, the first Action frame is broadcasted to a private station through a wireless channel, and the original Beacon frame is obtained by decrypting the head of the private station. Secondly, an original probe request frame is generated and encrypted to obtain an encrypted probe request frame, the encrypted probe request frame is encapsulated into a self-defined private station Action frame and an identifier is added to obtain a second Action frame, the second Action frame is sent to the access point and processed to obtain a private station Action frame, and finally, the original probe request frame is obtained by decryption. The application simplifies the invalid encryption and decryption operation process, and effectively improves the scanning discovery speed and system response efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, in particular to a wireless image transmission method based on a private Wi-Fi network secure connection. BACKGROUND

[0002] Wireless image transmission mainly relies on wireless communication technologies such as Wi-Fi to realize real-time transmission of image data, and combines image processing and coding and decoding technologies to ensure efficient and stable data transmission.

[0003] A general Wi-Fi infrastructure communication system has a hotspot, and multiple devices need to be connected to the AP to realize mutual communication. In order to enable the STA to connect to the AP, the AP often needs to broadcast Beacon to enable the STA to discover and connect. In addition, the hidden AP also needs the STA to scan by carrying the SSID of the AP, and the AP replies to the scanning, so as to achieve the purpose of discovery and connection. For a wireless image transmission system, because the AP and the STA are private and not visible to the outside, the above general Wi-Fi mode has the following shortcomings in security: broadcasting Beacon can easily expose the private network; using the hidden sending end mode, once the SSID is known by the outside, the external device can normally connect to the private AP through active scanning, thereby affecting the security; the general Wi-Fi mode encrypts the transmission data, but the key negotiation process is not encrypted, which is easy to be disturbed or attacked. SUMMARY

[0004] The technical problem solved by the present application is that the prior art can easily expose the private network through the broadcast Beacon frame; and using the hidden sending end mode, the external device can also normally connect to the private AP through active scanning, thereby affecting the security.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] A wireless image transmission method based on a private Wi-Fi network secure connection, comprising:

[0007] Step S1: generating an original Beacon frame conforming to the Wi-fi standard and encrypting the original Beacon frame to obtain an encrypted Beacon frame, taking an access point as a sending end;

[0008] Step S2: constructing an access point Action frame, encapsulating the encrypted Beacon frame into the access point Action frame as a net load and adding an identifier to obtain a first Action frame;

[0009] Step S3, taking the private station as a receiving end, the first Action frame is broadcasted to the private station through a wireless channel, the private station decrypts the first Action frame to obtain the original Beacon frame;

[0010] Step S4, taking each private station as a sending end, the original probe request frame is generated and encrypted to obtain the encrypted probe request frame;

[0011] Step S5, constructing the private station Action frame, the encrypted probe request frame is encapsulated into the private station Action frame as a net load and an identifier is added to obtain the second Action frame;

[0012] Step S6, taking the access point as a receiving end, the second Action frame is sent to the access point through a single channel, the access point processes the second Action frame to obtain the private station Action frame, the private station Action frame is decrypted to obtain the original probe request frame.

[0013] As a preferred scheme of the wireless image transmission method based on the private Wi-Fi network security connection, the step S1 specifically comprises the following sub-steps:

[0014] Step S11, according to the Wi-fi standard, the original Beacon frame corresponding to the access point is obtained;

[0015] Step S12, the original Beacon frame is encrypted by using the private symmetric key to obtain the encrypted Beacon frame.

[0016] As a preferred scheme of the wireless image transmission method based on the private Wi-Fi network security connection, the step S2 specifically comprises the following sub-steps:

[0017] Step S21, the access point Action frame is constructed by using the Action frame format;

[0018] Step S22, the encrypted Beacon frame is embedded in the Payload of the access point Action frame to obtain the embedded Action frame;

[0019] Step S23, the head position of the embedded Action frame is inserted into the OUI identifier to obtain the first Action frame, the first Action frame comprises a MAC head, an OUI identifier and the encrypted Beacon frame.

[0020] As a preferred scheme of the wireless image transmission method based on the secure connection of the private Wi-Fi network, the step S3 comprises the following sub-steps:

[0021] Step S31, sending the first Action frame to the private station by using the wireless channel;

[0022] Step S32, screening the MAC header and the OUI identifier by the Wi-Fi driver of the private station, and obtaining the first Action frame;

[0023] Step S33, decrypting the Payload by using the private symmetric key of the step S12, and obtaining the decrypted original Beacon frame.

[0024] As a preferred scheme of the wireless image transmission method based on the secure connection of the private Wi-Fi network, the step S4 comprises the following sub-steps:

[0025] Step S41, inputting the SSID and the scanning request parameter into the private station, and generating the original probe request frame;

[0026] Step S42, encrypting the original probe request frame by using the private symmetric key, and obtaining the encrypted probe request frame;

[0027] The original probe request frame comprises the target SSID, the scanning request parameter and the MAC header.

[0028] As a preferred scheme of the wireless image transmission method based on the secure connection of the private Wi-Fi network, the step S5 comprises the following sub-steps:

[0029] Step S51, constructing the private station Action frame by using the private station;

[0030] Step S52, embedding the encrypted probe request frame into the Payload of the private station Action frame, and obtaining the embedded Action frame;

[0031] Step S53, inserting the OUI identifier into the header position of the embedded Action frame, and obtaining the second Action frame;

[0032] The second Action frame comprises the MAC header, the OUI identifier and the encrypted probe request frame.

[0033] As a preferred scheme of the wireless image transmission method based on the secure connection of the private Wi-Fi network, the step S6 comprises the following steps:

[0034] The access point listens to the channel as a receiving end to receive all frames, discards and does not respond when a standard ProbeRequest frame without an OUI identifier is received, and continues to process when a second Action frame is received;

[0035] The second Action frame is processed by removing the header to obtain an encrypted Probe Request frame, and the encrypted Probe Request frame is decrypted by using a private key to obtain an original Probe Request frame.

[0036] As a preferred scheme of the wireless image transmission method based on a private Wi-Fi network security connection, the processing logic of the private symmetric key is:

[0037] When the access point and the private station perform key exchange, the sending end encrypts the original key exchange data packet by using the private symmetric key to obtain an encrypted key exchange data packet, and the key exchange data packet includes an Authentication frame or any interactive frame in a four-way handshake process;

[0038] The encrypted key exchange data packet is encapsulated into a key exchange Action frame as a net load, the identifier is added to the header of the frame to obtain a third Action frame, the sending end sends the third Action frame to the receiving end through a wireless channel, the receiving end confirms that the frame is a legal frame by identifying the identifier after receiving the third Action frame, removes the Action frame header to obtain the encrypted key exchange data packet, decrypts the encrypted key exchange data packet by using the private symmetric key to restore the original key exchange data packet, and completes key negotiation according to a standard Wi-Fi protocol process.

[0039] As a preferred scheme of the wireless image transmission method based on a private Wi-Fi network security connection, the processing logic of the key exchange Action frame is:

[0040] The identifier is an OUI identifier same as the first Action frame and the second Action frame, and the OUI identifier exists in the header of the third Action frame in a clear text form.

[0041] As a preferred scheme of the wireless image transmission method based on a private Wi-Fi network security connection, the processing logic of the private station Action frame constructed by using the private station is:

[0042] The private station adopts an Action frame defined by an IEEE 802.11 standard as a basic frame mode, selects a field as a Vendor Specific as a self-defined frame, and defines a 3-byte OUI identifier as a unique identifier in a Payload, and the OUI identifier is a non-encrypted plaintext field.

[0043] The application has the advantages that: by encrypting a standard Beacon management frame as a whole and encapsulating the Beacon management frame in a vendor-defined Action frame for broadcasting, the existence and identification information of the network are completely invisible to any external general device. Meanwhile, the access point discards a standard Probe Request detection request in silence, and only responds to a private station request that has been subjected to the same encryption and encapsulation processing, thereby constituting a double concealment mechanism. Passive broadcasting does not leak, active detection does not respond, even if the network SSID is accidentally leaked, an external device cannot discover or connect to the network through conventional means, thereby fundamentally eliminating the risk of network scanning discovery and unauthorized access, and providing an invisible communication environment for unmanned aerial vehicle image transmission, security monitoring and the like.

[0044] Secondly, the application constructs an end-to-end whole-process communication security guarantee. The security strategy covers not only the network discovery stage, but also extends to the core key exchange process of connection establishment, and the Authentication frame and the key negotiation frame of the four-way handshake are also encrypted and self-defined, so that sensitive interaction information in the whole link establishment process exists in the form of ciphertext that cannot be parsed during air transmission, thereby effectively resisting eavesdropping, replay or man-in-the-middle attacks against the key negotiation process, so that the whole communication chain from network discovery to connection to data transmission is highly protected, and the anti-attack ability of the whole system is greatly improved.

[0045] While realizing high-level security, the application also takes into account system processing efficiency and compatibility. By embedding a plaintext organization unique identifier in the frame header, the receiving end can quickly identify and filter out the system frame at the driver layer or hardware layer, without decrypting all captured Action frames, thereby greatly reducing the burden of invalid encryption and decryption operations, and improving the scanning discovery speed and system response efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 A basic flowchart of a wireless image transmission method based on a private Wi-Fi network security connection according to an embodiment of the application is shown in the figure.

[0047] Figure 2 An encryption processing process diagram of an original Beacon frame is shown in the figure.

[0048] Figure 3 A flowchart of a Beacon frame from a sending end to a receiving end is shown in the figure.

[0049] Figure 4 Basic flow chart for access point receiving prob request frame;

[0050] Figure 5 Flow chart for sending private Action frame for private station;

[0051] Figure 6 Flow chart for receiving private Action frame for private station. DETAILED DESCRIPTION

[0052] In order to make the above objectives, features and advantages of the present application more apparent, more comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0053] Embodiments, with reference to Figure 1 , Figure 5 and Figure 6 , provide a wireless image transmission method based on private Wi-Fi network security connection, comprising:

[0054] Step S1, taking the access point as the sending end, generating the original Beacon frame conforming to the Wi-fi standard and encrypting to obtain the encrypted Beacon frame;

[0055] Step S2, constructing the access point Action frame, encapsulating the encrypted Beacon frame into the access point Action frame as the net load and adding the identifier to obtain the first Action frame;

[0056] Step S3, taking the private station as the receiving end, broadcasting the first Action frame to the private station through the wireless channel, and the private station deciphers the first Action frame to obtain the original Beacon frame;

[0057] Step S4, taking each private station as the sending end, generating the original probe request frame and encrypting to obtain the encrypted probe request frame;

[0058] Step S5, constructing the private station Action frame, encapsulating the encrypted probe request frame into the private station Action frame as the net load and adding the identifier to obtain the second Action frame;

[0059] Step S6, taking the access point as the receiving end, sending the second Action frame to the access point through the single channel, and the access point processes the second Action frame to obtain the private station Action frame, decrypts the private station Action frame to obtain the original probe request frame.

[0060] By broadcasting the whole encryption of the standard Beacon management frame and encapsulating it in the vendor-defined Action frame, the existence and identification information of the network are completely invisible to any external general device. At the same time, the access point discards the standard Probe Request detection request silently, and only responds to the private site request after the same encryption encapsulation processing, which constitutes a double concealment mechanism. Passive broadcast does not leak, active detection does not respond, even if the network SSID is accidentally leaked, external devices cannot discover or connect the network through conventional means, fundamentally eliminating the risk of network scanning discovery and unauthorized access, and providing a stealth communication environment for UAV image transmission, security monitoring and other applications.

[0061] Secondly, the application constructs an end-to-end full-process communication security guarantee. Its security strategy not only covers the network discovery stage, but also extends to the core key exchange process of connection establishment. The Authentication frame and the key negotiation frame such as 4-way handshake are also encrypted and customized encapsulated, so that the sensitive interaction information in the whole link establishment process exists in the form of ciphertext that cannot be parsed during air transmission, effectively resisting eavesdropping, replay or man-in-the-middle attacks against the key negotiation process. The whole communication chain from network discovery, connection to data transmission is highly protected, greatly improving the anti-attack ability of the whole system;

[0062] While realizing high-level security, the application also considers system processing efficiency and compatibility. By embedding a plaintext organization unique identifier in the frame header, the receiving end can quickly identify and filter out the system frame at the driver layer or hardware layer, without decrypting all captured Action frames, greatly reducing the burden of invalid encryption and decryption operations, and improving the scanning discovery speed and system response efficiency.

[0063] Step S1 specifically includes the following sub-steps:

[0064] Step S11, according to the Wi-fi standard, an original Beacon frame corresponding to the access point is obtained.

[0065] Step S12, the original Beacon frame is encrypted by using a private symmetric key to obtain an encrypted Beacon frame.

[0066] As one of the embodiments of the application, refer to Figure 2First, the Wi-Fi protocol stack of the access point (AP) constructs a Beacon frame according to the IEEE 802.11 standard, the Beacon frame including frame control, SSID, BSSID, capability information, supported rate, channel number, timestamp and beacon interval, then the entire content of the Beacon frame is encrypted using a pre-shared private symmetric key, since the standard Beacon frame is broadcast in plaintext, if not encrypted, the network existence and basic information will be directly exposed, the purpose of encryption is to change the Beacon frame content from plaintext to ciphertext, even if the frame is intercepted, external devices cannot read its content;

[0067] The entire Beacon frame is encrypted using a pre-aligned private symmetric key to generate a Beacon frame;

[0068] The problem of network exposure caused by broadcasting the Beacon frame in the prior art is mainly solved in the embodiment, by encrypting the content of the original Beacon frame, the information value of the original Beacon frame itself is eliminated, the content is prevented from being parsed by external devices, network identification information is prevented from being leaked, ciphertext payload is provided for subsequent encapsulation, and complete concealment of the access point information is realized.

[0069] Step S2 specifically includes the following sub-steps:

[0070] Step S21, an access point Action frame is constructed using an Action frame format;

[0071] Step S22, an encrypted Beacon frame is embedded in the Payload of the access point Action frame to obtain an embedded Action frame;

[0072] Step S23, the head position of the embedded Action frame is inserted into an OUI identifier to obtain a first Action frame, the first Action frame including a MAC header, an OUI identifier and an encrypted Beacon frame.

[0073] As one of the embodiments of the present application, refer to Figure 3The access point constructs a vendor-defined Action frame. The frame type field of the vendor-defined Action frame is indicated as Vendor Specific. The encrypted Beacon frame obtained in step S1 is completely placed in the Payload field of the Action frame, and a 3-byte non-encrypted plaintext field, i.e., the unique OUI identifier (0x00A0C5) of the system, is inserted in the frame header (at the beginning of the Vendor Specific Content field) of the Action frame. The encrypted Beacon frame is hidden in the vendor-defined frame, so that an external device cannot identify the type of the Beacon frame. The OUI identifier is used to realize fast filtering of the driver layer, solves the problem of fast identification without decryption, avoids uploading of invalid frames to the protocol stack, and improves the scanning rate.

[0074] Step S3 includes the following sub-steps:

[0075] Step S31, the first Action frame is sent to the private station by using the wireless channel.

[0076] Step S32, the private station screens the MAC header and the OUI identifier by using the Wi-Fi driver to listen to the channel, and obtains the first Action frame.

[0077] Step S33, the Payload is decrypted by using the private symmetric key in step S12, and the decrypted original Beacon frame is obtained.

[0078] As one of the embodiments of the application, the access point broadcasts and sends the first Action frame through the wireless channel. When the Wi-Fi driver layer of the private station listens to the channel, the frame header and the OUI field of all captured frames are matched and screened. When it is identified that the MAC header type is the Action frame and the OUI is 0x00A0C5, it is determined that the first Action frame is obtained and uploaded to the upper layer processing. The upper layer software removes the Action frame header, extracts the encrypted data in the Payload, and then decrypts the data by using the same private symmetric key. Finally, the original Beacon frame information is restored.

[0079] In the embodiment, steps S2 and S3 jointly constitute a one-way hidden network existence notification mechanism. For an external device, the self-defined Action frame cannot be identified through air transmission. For the private station, the interpretable network information mark is set, so that the problem of exposure caused by the broadcasted Beacon frame is solved.

[0080] Step S4 includes the following sub-steps:

[0081] Step S41, input SSID and scanning request parameters in the private site, generate an original probe request frame;

[0082] Step S42, encrypt the original probe request frame by using a private symmetric key, obtain an encrypted probe request frame;

[0083] The original probe request frame includes a target SSID, scanning request parameters and a MAC header.

[0084] Active scanning AP, construct a standard Probe Request frame, set the SSID field as the SSID of the target AP, and also use a private key to perform AES-256-GCM encryption on the entire Probe Request frame to generate an encrypted Probe Request frame;

[0085] Step S41 is used to construct a Probe Request frame (Probe Request frame) completely consistent with the IEEE 802.11 standard. The private site generates a Probe Request frame with a target SSID field of "Private_Net_123" according to the known private network name. The Probe Request frame also contains scanning request parameters and a standard MAC header. The scanning request parameters are a list of channels to be scanned and a supported rate set. The MAC header uses the MAC address of the private site itself as the source address and the broadcast address or a specific BSSID as the target address. This step is used to generate a standard connection query request for a specific private network.

[0086] Step S42 mainly includes: the private site uses a private symmetric key pre-shared with the access point to perform encryption operation on the entire Probe Request frame (including MAC header, SSID and all fields) generated in step S41 to generate a piece of ciphertext, i.e. an encrypted Probe Request frame. This step is used to convert the standard network detection request into ciphertext to hide the target network SSID, sender identity (MAC address) and capability set information.

[0087] Step S5 includes the following sub-steps:

[0088] Step S51, construct a private site Action frame by using the private site;

[0089] Step S52, embed the encrypted probe request frame in the Payload of the private site Action frame to obtain an embedded Action frame;

[0090] Step S53, inserting the OUI identifier in the head position of the embedded Action frame, obtaining a second Action frame;

[0091] The second Action frame includes a MAC header, an OUI identifier and an encrypted probe request frame.

[0092] The private station protocol stack creates an empty Action frame structure, sets the category field of the empty Action frame to Vendor Specific (value 127) to indicate a vendor-defined frame, and places the encrypted Probe Request frame obtained in step S42 into the Payload (net load) field of the Action frame created in step S51 in its entirety; the starting position of the Vendor Specific Content area of the Action frame filled with the encrypted payload is inserted with a 3-byte plaintext OUI identifier to generate a complete second Action frame, and the structure of the second Action frame is: standard MAC header, Action frame header (including Vendor Specific indication), OUI identifier, encrypted Probe Request ciphertext payload, solving the key problem of fast identification and filtering. The plaintext OUI is the only basis for the legitimate access point to achieve hardware-level fast filtering at the physical layer or driver layer when receiving a large number of wireless frames.

[0093] Step S6 specifically includes:

[0094] The access point is taken as a receiving end to listen to the channel and receive all frames, when a standard ProbeRequest frame without an OUI identifier is received, it is directly discarded without response, and when a second Action frame is received, it is further processed;

[0095] The second Action frame is processed to remove the header to obtain an encrypted Probe Request frame, and the encrypted Probe Request frame is decrypted using a private key to obtain an original Probe Request frame.

[0096] In this embodiment, reference is made to Figure 4 For each frame received:

[0097] If it is a standard Probe Request frame without OUI identifier, the driver or underlying firmware of the access point checks and finds that the frame is a standard Management frame and does not contain the OUI identifier agreed by the system, the access point performs a silent discard process on such frame and does not generate any Probe Response reply and does not record in the log; if it is a second Action frame containing a correct OUI, the hardware filter or driver of the access point identifies that the frame is an Action frame and the OUI identifier matches, determines that it is a request from a legitimate private station, and submits the Action frame to the upper layer protocol stack for further processing; for the second Action frame identified as legitimate, the upper layer protocol software of the access point strips the MAC header and the Action frame header, extracts the encrypted Probe Request ciphertext immediately following the OUI identifier, and then the access point uses the same private symmetric key as the private station to decrypt the ciphertext, which is conducive to the conversion of private signaling to standard signaling.

[0098] The processing logic of the private symmetric key is as follows:

[0099] When the access point and the private station perform key exchange, the sending end encrypts the original key exchange data packet using the private symmetric key to obtain an encrypted key exchange data packet. The key exchange data packet includes an Authentication frame or any interactive frame in the four-way handshake process.

[0100] An encrypted key exchange data packet is constructed, the encrypted key data packet is encapsulated into the key exchange Action frame as the net load, and an identifier is added to the frame header to obtain a third Action frame. The sending end sends the third Action frame to the receiving end through the wireless channel. After receiving the third Action frame, the receiving end confirms that it is a legal frame by identifying the identifier, removes the Action frame header to obtain the encrypted key exchange data packet, and decrypts it using the private symmetric key to restore the original key exchange data packet. The key negotiation is completed according to the standard Wi-Fi protocol process.

[0101] In this embodiment, when the access point and the private station need to perform authentication or four-way handshake, the sender can be the access point or the private station. When the sender generates a standard EAPOL frame (such as an authentication frame or Msg1-Msg4 of four-way handshake), the sender immediately encrypts the entire content of the frame using the same private symmetric key; the sender constructs a new Vendor Specific Action frame with the same format as the second Action frame, uses the encrypted key exchange data packet as the Payload of the frame, and inserts the OUI identifier (0x00A0C5) in plaintext in the header of the frame to form a third Action frame. The sender sends the third Action frame through the wireless channel in unicast mode. The receiver identifies and receives the frame by listening and OUI filtering. The receiver removes the header and decrypts the Payload using the private symmetric key to restore the original EAPOL frame. Then, the receiver gives the EAPOL frame to the standard Wi-Fi security subsystem (such as the WPA2 / WPA3 module) for normal authentication and key agreement calculation, ensures that the interaction process is not perceived and disturbed by a bystander, and realizes hierarchical security mechanisms.

[0102] The processing logic of the key exchange Action frame is as follows:

[0103] The identifier is the same OUI identifier as the first Action frame and the second Action frame, and the OUI identifier exists in the header of the third Action frame in plaintext.

[0104] In this embodiment, the identifier used by the third Action frame for encapsulating the key exchange data is the same OUI identifier as the identifier used by the first Action frame for encapsulating the Beacon and the identifier used by the second Action frame for encapsulating the Probe Request. Therefore, all security management frames of the entire private network system have unified external characteristics, which simplifies the identification logic of the access point and the private station, and makes it impossible for an attacker to distinguish these frames from each other and initiate an attack on a specific stage.

[0105] The processing logic of the private station Action frame constructed by the private station is as follows:

[0106] The private station uses the Action frame defined in the IEEE 802.11 standard as the basic frame mode, selects the Vendor Specific field as the custom frame, defines a 3-byte OUI identifier as the unique identifier in the Payload, and the OUI identifier is a non-encrypted plaintext field.

[0107] The IEEE 802.11 standard protocol used in the embodiment explicitly reserves frame types for vendor extension and future function definition, ensuring maximum compliance and coexistence with existing Wi-Fi devices, neither interfering with other normal networks, nor passing the relevant radio frequency certification, which is conducive to improving the real-time rate of battery-powered mobile devices and image transmission.

[0108] Those skilled in the art will understand that embodiments of the present application can be provided as methods, systems or computer program products. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code. The storage media can be realized by any type of volatile or non-volatile storage devices or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk. These computer program instructions can also be stored in a computer readable storage medium that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable storage medium produce a product including instruction means, which realize the functions specified in the flowcharts Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks

[0109] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalent ones without departing from the spirit and scope of the present application, which should be covered by the protection scope of the present application.

Claims

1. A wireless image transmission method based on a secure private Wi-Fi network connection, characterized in that, include: Step S1: The access point is used as the sending end to generate a raw Beacon frame that conforms to the Wi-Fi standard and encrypt it to obtain an encrypted Beacon frame. Step S2: Construct an access point Action frame by encapsulating the encrypted Beacon frame as the payload into the access point Action frame and adding an identifier to obtain the first Action frame. Step S3: Using the private site as the receiving end, the first Action frame is broadcast to the private site via the wireless channel. The private site decrypts the first Action frame by removing the header to obtain the original Beacon frame. Step S4: Generate and encrypt the original probe request frame by sending each private site as the sender to obtain the encrypted probe request frame. Step S5: Construct a private site Action frame by encapsulating the encrypted probe request frame as the payload into the private site Action frame and adding an identifier to obtain the second Action frame. Step S6: Using the access point as the receiving end, the second Action frame is sent to the access point via a single channel. The access point removes the header of the second Action frame to obtain the private site Action frame. The private site Action frame is then decrypted to obtain the original probe request frame.

2. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 1, characterized in that, Step S1 specifically includes the following sub-steps: Step S11: Obtain the original Beacon frame corresponding to the access point according to the Wi-Fi standard; Step S12: Use the private symmetric key to encrypt the original Beacon frame to obtain an encrypted Beacon frame.

3. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 2, characterized in that, Step S2 specifically includes the following sub-steps: Step S21: Construct an access point Action frame using the Action frame format; Step S22: Embed an encrypted Beacon frame in the payload of the access point Action frame to obtain the embedded Action frame; Step S23: Insert the OUI identifier into the header position of the embedded Action frame to obtain the first Action frame, which includes a MAC header, an OUI identifier, and an encrypted Beacon frame.

4. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 3, characterized in that, Step S3 includes the following sub-steps: Step S31: Send the first Action frame to the private site using the wireless channel; Step S32: The private site filters the MAC header and OUI identifier through the Wi-Fi driven listening channel to obtain the first Action frame; Step S33: Decrypt the Payload using the private symmetric key obtained in step S12 to obtain the decrypted original Beacon frame.

5. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 4, characterized in that, Step S4 includes the following sub-steps: Step S41: Enter the SSID and scan request parameters on the private site to generate the original probe request frame; Step S42: Encrypt the original probe request frame using the private symmetric key to obtain an encrypted probe request frame; The original probe request frame includes the target SSID, scan request parameters, and MAC header.

6. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 5, characterized in that, Step S5 includes the following sub-steps: Step S51: Construct a private site Action frame using the private site; Step S52: Embed an encrypted probe request frame in the payload of the private site Action frame to obtain the embedded Action frame; Step S53: Insert an OUI identifier into the header position of the embedded Action frame to obtain the second Action frame; The second Action frame includes a MAC header, an OUI identifier, and an encrypted probe request frame.

7. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 6, characterized in that, Step S6 specifically includes: The access point is used as the receiving end listening channel to receive all frames. When a standard ProbeRequest frame without an OUI identifier is received, it is discarded without response. When a second Action frame is received, it is processed. Remove the header from the second Action frame to obtain an encrypted Probe Request frame. Decrypt the encrypted Probe Request frame using the private key to obtain the original Probe Request frame.

8. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 6, characterized in that, The processing logic for the private symmetric key is as follows: When exchanging keys between the access point and the private site, the sending end encrypts the original key exchange data packet using the private symmetric key to obtain an encrypted key exchange data packet, which includes an Authentication frame or any interaction frame in the four-way handshake process. A key exchange Action frame is constructed, and the encrypted key exchange data packet is encapsulated as the payload into the key exchange Action frame. The identifier is added to the frame header to obtain the third Action frame. The sending end sends the third Action frame to the receiving end through the wireless channel. After receiving the third Action frame, the receiving end identifies it as a valid frame by recognizing the identifier, removes the Action frame header to obtain the encrypted key exchange data packet, and decrypts it using the private symmetric key to restore the original key exchange data packet. The key negotiation is then completed according to the standard Wi-Fi protocol process.

9. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 8, characterized in that, The processing logic for the key exchange Action frame is as follows: The identifier is the same OUI identifier as the first Action frame and the second Action frame, and the OUI identifier exists in plaintext form in the header of the third Action frame.

10. The wireless image transmission method based on a private Wi-Fi network security connection as described in claim 9, characterized in that, The processing logic for constructing a private site Action frame using a private site is as follows: The private site uses the Action frame defined by the IEEE 802.11 standard as the basic frame mode, selects the VendorSpecific field as the custom frame, and defines a 3-byte OUI identifier as a unique identifier in the payload. The OUI identifier is an unencrypted plaintext field.

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