Position-dependent security information transmission device based on visible polarized light interference

Abstract

The application provides a position-related security information transmission device based on visible polarized light interference, and belongs to the technical field of Internet of Things device information transmission, and comprises a light signal transmitting end and a receiving end; a device capable of emitting polarized light and changing incident spectrum is used as a transmitter for emitting polarized light; a linear polarizer is used for measuring the polarization direction, and a plurality of birefringent materials are fixed on the linear polarizer; for the light signal receiving end, a device capable of distinguishing colors is used as a light signal receiver. The application is based on the birefringent characteristics and interference of visible polarized light, so that the spectra obtained at different distances and different directions are different, thereby different information can be transmitted to receivers at different positions, and the multiple transmission of information is realized; only the information received by the specified position is correct, so that the security of information transmission is ensured. Meanwhile, the information is encoded, so that the code information obtained at different positions is different, so that it is difficult for an attacker to decode the correct information.

Description

Technical Field

[0001] This invention relates to the field of information transmission technology for Internet of Things (IoT) devices, and specifically to a position-related security information transmission device based on visible polarization light interference. Background Technology

[0002] With the advent of the digital age, the demand for high-speed data transmission is constantly increasing. In recent years, visible light-based information transmission technology has developed rapidly. It is a new type of information transmission method developed based on traditional wireless communication technology. Compared with wireless communication technologies with limited spectrum resources, it has many advantages, such as abundant spectrum resources, higher spectrum efficiency, energy saving and environmental protection, and less interference. However, because visible light-based information transmission technology can be compromised by attackers using specific information receiving or interception devices when transmitting optical signals to the receiver, it currently suffers from security issues.

[0003] Existing visible light-based information transmission technologies are based on the principles of light transmission and communication, using light transmitters to generate visible light signals and transmit data to specific receivers.

[0004] In existing visible light-based information transmission technologies, devices such as lasers and light-emitting diodes (LEDs) are commonly used as light emitters. They transmit encoded data by altering the characteristics of the light signal (such as turning the light source on and off, the emission frequency, and the emission intensity). The receiving end typically uses photosensitive devices (such as photodiodes and cameras) as receivers to receive the light signal. Once the light signal reaches the receiver, it is decoded and converted into digital or electrical signals to recover the original data information.

[0005] Visible Light Communication (VLC) is an emerging wireless communication technology that uses the visible light band to transmit information. It uses LEDs as a light source, causing the light source to flash at an extremely fast speed, emitting rapidly changing light signals to transmit specified information.

[0006] Taking on-off keying (OOK) transmission technology as an example, it uses binary digits 1 and 0 to represent the intensity of the light signal (i.e., "bright" and "dark" states), respectively. By converting the data to be transmitted into binary digits for encoding, a fixed-frequency carrier signal is generated at the transmitting end. When the binary digit value is 1, the transmitting end sends a high-intensity signal; when the binary digit value is 0, a low-intensity signal is sent. After acquiring the signal, the receiving end amplifies it to enhance its quality, then uses threshold detection to determine the strength of the light signal, and reconstructs the data information from the binary signal based on the detection result. Therefore, when the communication rate of a visible light communication system is very high, the human eye cannot easily detect the rapidly changing light information, while the receiver can detect changes in the intensity of the light signal, thus realizing visible light communication. Furthermore, the signal coverage area of ​​visible light communication is easy to control. Due to the characteristics of light propagation, the signal coverage area can be flexibly adjusted using common everyday objects.

[0007] In current visible light communication technologies, Frequency Shift Keying (FSK) is frequently used for information transmission. This technology binds the frequency of the light signal emitted by the transmitter to binary information; that is, different light signal frequencies transmit different binary information. Furthermore, when combined with multiplexing technology, multiple low-frequency channels can be combined into a single high-frequency channel, greatly improving data link utilization and information transmission efficiency. This technology can also transmit specific information to different devices using different frequencies. Similar to FSK, Color Shift Keying (CSK) also plays a crucial role in visible light communication. This technology uses different colors to represent different binary information, enabling the transmission of binary codes using color signals.

[0008] In terms of improving the communication rate of visible light, technologies such as bandwidth expansion, higher-order modulation, and wavelength division multiplexing are also widely used. For example, researchers at Fudan University used five-color LEDs as light sources and adopted Discrete Multitone (DMT) modulation technology to greatly improve the communication rate of visible light.

[0009] A publicly available positioning technique based on visible polarized light interferometry is based on the fact that light passing through a polarizer and birefringent materials will produce different interference patterns and spectra in different directions. A model was analyzed and derived as the basis for 3D positioning. Based on this model, researchers proposed a method for 3D positioning using ambient light with low deployment, maintenance and usage costs.

[0010] Existing technologies suffer from low security: Currently, visible light-based information transmission technologies transmit information through free space to the receiver. Attackers can use specialized equipment (such as cameras or photodiodes) to acquire or intercept specific information sent to the receiver, and then analyze the characteristics of the light signal and decode it to obtain the original data. While some visible light-based information transmission technologies use cryptographic methods to add encryption and decryption steps to the information transmission process, improving security to some extent, this also increases the workload and computational burden, raising the cost of information transmission. Furthermore, in wireless communication scenarios, attackers can also intercept information transmitted by the transmitter. Summary of the Invention

[0011] The purpose of this invention is to provide a position-related security information transmission device based on visible polarized light interference, so as to solve at least one of the technical problems existing in the background art.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A position-related security information transmission device based on visible polarized light interference includes two parts: a transmitting end and a receiving end for optical signals. For the transmitting end, a device capable of emitting polarized light and changing the incident spectrum is used as the transmitter to emit polarized light. The polarization direction is measured using a linear polarizer, and several birefringent materials are fixed on the linear polarizer. For the receiving end, a device capable of distinguishing colors is used as the receiver for the optical signals.

[0014] Furthermore, the polarized light emitted by the transmitter enters from one end of the birefringent material. After passing through the birefringent material and the linear polarizer, the incident light exits from one end of the linear polarizer and is finally captured by the receiver to receive the specified information.

[0015] Furthermore, the transmitter emits polarized light with variable spectrum, fixes multiple birefringent materials on a linear polarizer, adjusts the positional relationship between the birefringent materials and the angle between their optical axes and the polarized light emitted by the transmitter; uses a color-distinguishing device as a receiver to acquire information at a designated information receiving point, and performs color analysis on each transmitted light signal after receiving the information.

[0016] The beneficial effects of this invention are as follows: Based on the birefringence and interference properties of visible polarized light, different spectra are obtained at different distances and orientations. This allows different information to be transmitted to receivers at different locations, achieving multipath propagation of information. Among these multiple receiving locations, only the designated location receives the correct information, thus ensuring the security of information transmission. Simultaneously, the information is encoded so that the code information obtained at different locations is different, making it very difficult for attackers to decode the correct information.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments 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.

[0019] Figure 1 This is a structural diagram of a position-related security information transmission device based on visible polarization light interference, as described in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram illustrating the working principle of the position-related security information transmission device based on visible polarized light interference, as described in an embodiment of the present invention.

[0021] Wherein: 1-transmitter; 2-linear polarizer; 3-birefringent material; 4-receiver. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0025] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0026] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0027] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In the description of this specification, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this technology.

[0029] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of these terms in this art according to the specific circumstances.

[0030] To facilitate understanding of the present invention, the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0031] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0032] This embodiment provides a position-related secure information transmission device based on visible polarized light interference, aiming to improve the security of visible light-based information transmission technology. The following technical issues need to be addressed: (1) How to utilize the characteristics of light (such as polarization, interference, and birefringence) and the physical properties of experimental materials to design suitable visible light-based information transmission devices and schemes. (2) How to achieve directional and point-to-point information transmission targeting the receiver's location, preventing attackers from successfully receiving information sent to a designated receiver using their own receiving devices. (3) How to ensure that even if an attacker intercepts the light signal using an interception device, they cannot reconstruct the correct information, thereby guaranteeing the security of information transmission. (4) How to design suitable encoding-decoding algorithms to prevent attackers from successfully decoding the information after obtaining it, achieving reliable information transmission and reconstruction.

[0033] The purpose of this invention is to utilize the characteristics of visible polarized light, causing incident light to produce different spectra at different distances and orientations after birefringence and interference, thereby achieving multi-channel information transmission based on the receiver's location. Since the attacker's location and the designated receiver's location will inevitably differ, the spectral information acquired by the attacker and the designated receiver will be different, meaning the attacker cannot successfully obtain the correct information. Even if the attacker uses specific interception devices to intercept information, the difference between the interception location and the receiver's location will lead to inconsistencies between the intercepted information and the correct information. Furthermore, by encoding the transmitted information, the security of information transmission is further improved. Simultaneously, this invention changes the incident spectrum, causing the emitted spectrum received at the same location to continuously change, allowing the receiver to continuously acquire changing information. Therefore, variable information can be transmitted directionally and precisely based on the receiver's specific location. At the same time, it ensures that the information transmitted to the receiver cannot be acquired or decoded by the attacker, greatly guaranteeing the security of information transmission.

[0034] This invention addresses the shortcomings of existing visible light-based information transmission devices by designing a novel position-related security information transmission device based on visible polarized light interference. The device comprises two parts: a transmitting end and a receiving end for optical signals, such as... Figure 1 As shown. For the emitting end of the optical signal, a device capable of emitting polarized light and changing the incident spectrum is used as the emitter 1 (such as a liquid crystal display) to emit polarized light. The polarization direction is measured using a linear polarizer, and then several birefringent materials 3 are fixed onto the linear polarizer 2. For the receiving end of the optical signal, a device capable of distinguishing colors is used as the receiver 4 of the optical signal (such as a camera or photodiode).

[0035] When the secure information transmission device of the present invention is used, polarized light emitted by the transmitter enters from one end of the birefringent material. After passing through the birefringent material and the linear polarizer, the incident light exits from one end of the linear polarizer. Finally, the receiver captures the optical signal and receives the specified information.

[0036] like Figure 2 The transmitter emits polarized light. Two polarized beams, L1 and L2, enter a birefringent material at points A and B, respectively, resulting in birefringence. L1 splits into two refracted beams: L1o (ordinary ray) and L1e (extraordinary ray), and L2 also splits into two refracted beams: L2o (ordinary ray) and L2e (extraordinary ray). As shown in the figure, L1e and L2o interfere at point C, and the interfered light is captured by the receiver. Because the light undergoes interference and birefringence, the resulting spectrum differs at different orientations and distances, meaning the color information of the received light signal varies at different locations. Since the attacker and receiver are in different positions, the attacker cannot obtain the correct information about the receiver's location, thus ensuring the security of this invention.

[0037] Furthermore, when the incident spectrum emitted by the transmitter changes, the emitted spectrum also changes accordingly, so the receiver can continuously receive the changing light information.

[0038] For the fabrication of the device, a transmitter capable of emitting polarized light with variable spectra is used. Multiple birefringent materials are then fixed onto a linear polarizer, and the positional relationship between the birefringent materials and the angle between their optical axes and the polarized light emitted by the transmitter are adjusted. A color-distinguishing device is used as a receiver to acquire information at a designated receiving point. After receiving the information, color analysis is performed on each transmitted light signal.

[0039] In summary, the position-related security information transmission device based on visible polarized light interference described in this invention innovatively utilizes the polarization, interference, and birefringence properties of light to bind spectral information of different wavelengths with the information to be transmitted, ensuring that the received spectra at different locations differ, thereby improving the security of information transmission. A device capable of emitting polarized light and altering the incident spectrum is used as the transmitter; birefringent materials are used to induce birefringence in the incident light; and a color-distinguishing device is used as the receiver.

[0040] This invention utilizes the birefringence and interference properties of polarized light, as well as the physical properties of birefringent materials, to split incident light into two refracted beams after entering the birefringent material. The refracted beams of different incident beams interfere with each other, thereby transmitting different spectral information to different locations, solving technical problem (1). Since the attacker's location and the designated receiver must be different, the spectrum obtained by the attacker must be different from the correct spectrum transmitted to the designated location, solving technical problem (2). Even if the attacker intercepts the light signal, the intercepted information will differ from the correct information due to the deviation between the interception location and the receiver's location, solving technical problem (3). By encoding the color attributes of the light signal, only the correct code information is transmitted to the designated receiver, while the information transmitted to other locations is a deceptive erroneous code information encoded based on incorrect spectral information, making it difficult for the attacker to successfully decode, solving technical problem (4).

[0041] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions disclosed in the present invention, various modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present invention.

Claims

1. A position-related security information transmission device based on visible polarized light interference, characterized in that, include: The optical signal consists of two parts: the transmitting end and the receiving end. The transmitting end of the optical signal includes: a device that can emit polarized light and change the incident spectrum as a transmitter; and a linear polarizer, with several birefringent materials fixed on the linear polarizer; the polarized light emitted by the transmitter enters from one end of the birefringent materials, and after passing through the birefringent materials and the linear polarizer, the incident light exits from one end of the linear polarizer; wherein the positional relationship between the birefringent materials and the angle between their optical axes and the polarized light emitted by the transmitter are adjustable; the receiving end includes: a device that can distinguish colors as a receiver of the optical signal, the receiver captures the optical signal, acquires information at a designated information receiving point, and performs color analysis on each transmitted optical signal after receiving the information.

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