CN117478236A - Position-dependent security information transmission device based on visible polarized light interference - Google Patents

Abstract

The invention provides a position-related safety information transmission device based on visible polarized light interference, which belongs to the technical field of information transmission of Internet of things equipment, and comprises a transmitting end and a receiving end of an optical signal, wherein equipment capable of emitting polarized light and changing an incident spectrum is used as a transmitter for emitting the polarized light; measuring the polarization direction by using a linear polarizer, and fixing a plurality of birefringent materials on a linear polarizer; for the receiving end of the optical signal, a device that can distinguish colors is used as the receiver of the optical signal. Based on the birefringence characteristics and the interference of the visible polarized light, the optical spectrums obtained in different distances and different directions are different, so that different information can be transmitted to receivers in different positions, and multipath propagation of the information is realized; only the designated position receives the correct information, thereby ensuring the safety of information transmission. Meanwhile, the information is encoded so that the code information obtained from different positions is different, so that an attacker can hardly decode the correct information.

Description

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

Technical Field

The invention relates to the technical field of information transmission of equipment of the Internet of things, in particular to position-related safety information transmission equipment based on visible polarized light interference.

Background

With the advent of the digitization age, the need for high-speed data transmission has been increasing. In recent years, information transmission technology based on visible light is more and more different, and is a novel information transmission mode developed based on the traditional wireless communication technology. It has many advantages over wireless communication technologies with limited spectrum resources, such as rich spectrum resources, high spectrum efficiency, energy conservation, environmental protection, less interference, etc. However, since the information transmission technology based on visible light can be used by an attacker to acquire an optical signal using a specific information receiving apparatus or information intercepting apparatus when transmitting the optical signal to a receiver, the conventional information transmission technology based on visible light generally has a problem of low security.

The existing information transmission technology based on visible light is based on the transmission and communication principle of light, and utilizes a light emitter to generate a visible light signal to transmit data to a specific receiver.

In the existing technology of information transmission based on visible light, a laser, a light emitting diode (Light Emitting Diode, LED) and the like are often used as a light emitter, and the coded data is transmitted by changing the characteristics of the light signal (such as on and off of a light source, a light emitting frequency, a light emitting intensity and the like). The receiving end generally uses a photosensitive device (such as a photodiode, a camera, etc.) as a receiver to receive the optical signal, decodes the optical signal after reaching the receiver, and converts the optical signal into a digital signal or an electrical signal, thereby recovering the original data information.

Visible light communication (Visible Light Communication, VLC) is an emerging wireless communication technology that utilizes the visible light band for information transmission. It uses LEDs as light sources, causing the light sources to blink at an extremely fast rate, emitting a high-speed varying optical signal, and transmitting the specified information.

Taking On-off keying (OOK) transmission technology as an example, binary digits 1 and 0 are used to represent the intensity of an optical signal respectively (i.e. two states of "bright" and "dark"), the data information to be transmitted is converted into binary digits to be encoded, a carrier signal with a fixed frequency is generated at a transmitting end, when the binary digit has a value of 1, the transmitting end transmits a signal with high intensity, and when the binary digit has a value of 0, the transmitting end transmits a signal with low intensity. After the receiving end acquires the signal, the signal is amplified to enhance the quality of the signal, then threshold detection is used for judging the intensity of the optical signal, and the recovery from the binary signal to the data information is realized according to the detection result. Therefore, when the communication rate of the visible light communication system is large, it is difficult for the human eye to capture the optical information changing at high speed, and the receiver can detect the change in intensity of the optical signal, thereby realizing the visible light communication. Meanwhile, the signal coverage area of the visible light communication is easy to control, and due to the characteristic of light propagation, the signal coverage area can be flexibly adjusted only by using common shielding objects in life.

In the current visible light communication technology, frequency keying (Frequency Shift Keying, FSK) technology is also often used for information transmission. The technology binds the frequency of the optical signal emitted by the emitter and the binary information, namely, when the frequency of the optical signal is different, the transmitted binary information is different. And, after combining with multiplexing technology, a plurality of low frequency channels can be combined into one high frequency channel, thereby greatly improving the utilization rate of the data link and the information transmission efficiency. Meanwhile, the technology can also transmit the appointed information to different devices through different frequencies. Similar to the frequency keying technique, the color keying (Color Shift Keying, CSK) technique plays an important role in the field of visible light communication. The technique achieves the function of transmitting binary codes using color signals by using different colors to represent different binary information.

In terms of improving the communication rate of visible light, the technologies of bandwidth expansion, high-order modulation, wavelength division multiplexing and the like are also widely used, for example, scientific researchers at the university of complex denier use 5-color LEDs as light sources, and adopt a discrete multi-tone (Discrete Multi Tone, DMT) modulation technology, so that the rate of visible light communication is greatly improved.

The prior disclosed positioning technology based on visible polarized light interference is based on that light passing through a polarizer and a birefringent material can generate different interference patterns and spectrums in different directions, a model is analyzed and deduced as a basis of three-dimensional positioning, and based on the model, researchers propose a method for three-dimensional positioning by using ambient light with low deployment, maintenance and use costs.

The prior art mainly has the defect of lower safety: currently, in the process of transmitting information, the visible light-based information transmission technology transmits visible light information to a receiver through free space, so that an attacker can acquire or intercept designated information sent to the receiver by using special equipment (such as a camera or a photodiode), and then acquire original data information by analyzing the characteristics of an optical signal and decoding the signal. While some information transmission technologies based on visible light add encryption and decryption links to the information transmission process by using a cryptography method on the basis, the security of visible light communication is improved to a certain extent, but the corresponding workload and calculation amount are increased, and the cost of information transmission is increased. Furthermore, in the context of wireless communications, an attacker may also capture information sent by the transmitter.

Disclosure of Invention

The invention aims to provide a position-related safety information transmission device based on visible polarized light interference, so as to solve at least one technical problem in the background art.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a position-dependent security information transmission device based on visible polarized light interference, comprising: a transmitting end and a receiving end of the optical signal; for the transmitting end of the optical signal, a device capable of emitting polarized light and changing the incident spectrum is used as an emitter for emitting polarized light; measuring the polarization direction by using a linear polarizer, and fixing a plurality of birefringent materials on a linear polarizer; for the receiving end of the optical signal, a device capable of distinguishing colors is used as the receiver of the optical signal.

Further, polarized light emitted from the emitter enters from one end of the birefringent material, and after passing through the birefringent material and the linear polarizer, the incident light exits from one end of the linear polarizer, and finally, an optical signal is captured by the receiver and designated information is received.

Further, the emitter emits polarized light with variable spectrum, a plurality of birefringent materials are fixed on the linear polaroid, and the position relation among the birefringent materials and the included angle between the optical axes of the birefringent materials and the polarized light emitted by the emitter are adjusted; the device capable of distinguishing colors is used as a receiver, information is acquired at an information receiving point at a designated position, and color analysis is carried out on each transmitted optical signal after the information is received.

The invention has the beneficial effects that: based on the double refraction characteristics and the interference of the visible polarized light, the spectra obtained by different distances and different directions are different, so that different information can be transmitted to receivers at different positions, and the multipath propagation of the information is realized. And among the plurality of receiving positions, only the designated position receives correct information, so that the safety of information transmission is ensured. Meanwhile, the information is encoded so that the code information obtained from different positions is different, so that an attacker can hardly decode the correct information.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a diagram of a position-dependent security information transmission device based on visible polarized light interference according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of operation of a position-related security information transmission device based on visible polarized light interference according to an embodiment of the present invention.

Wherein: 1-an emitter; 2-linear polarizer; 3-birefringent material; 4-receiver.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functionality. The embodiments described below by way of the drawings are exemplary only and should not be construed as limiting the invention.

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

It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or groups thereof.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

In the description of this specification, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present specification, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present technology.

The terms "mounted," "connected," and "disposed" are to be construed broadly, and may be, for example, fixedly connected, disposed, detachably connected, or integrally connected, disposed, unless otherwise specifically defined and limited. The specific meaning of the above terms in the present technology can be understood by those of ordinary skill in the art according to the specific circumstances.

In order that the invention may be readily understood, a further description of the invention will be rendered by reference to specific embodiments that are illustrated in the appended drawings and are not to be construed as limiting embodiments of the invention.

It will be appreciated by those skilled in the art that the drawings are merely schematic representations of examples and that the elements of the drawings are not necessarily required to practice the invention.

The embodiment provides a position-related security information transmission device based on visible polarized light interference, which aims to improve the security of the information transmission technology based on visible light, and aims to solve the following technical problems: (1) How to design a proper information transmission device and information transmission scheme based on visible light by utilizing the characteristics (such as polarization, interference, birefringence and the like) of light and the physical properties of experimental materials. (2) How to realize the information transmission of the directional fixed point of the position of the receiver, so that the attacker cannot successfully receive the information sent to the appointed receiver through the receiving device of the attacker. (3) How to enable an attacker to recover correct information even if the optical signal is intercepted by using the interception device, thereby guaranteeing the safety of information transmission. (4) How to design a proper coding-decoding algorithm to prevent the information from being successfully decoded after being acquired by an attacker, and realize reliable transmission and restoration of the information.

The invention aims to utilize the characteristics of visible polarized light to enable incident light to generate different spectrums at different distances and different directions after double refraction and interference, thereby realizing multipath information transmission based on the position of a receiver. Because the position of the attacker is necessarily different from that of the appointed receiver, the spectrum information acquired by the attacker is different from that acquired by the appointed receiver, namely the attacker cannot successfully acquire the correct information. Even if an attacker uses a specific interception device to intercept information, inconsistency between the intercepted information and correct information can be caused by the difference between the information interception position and the receiver position. And the safety of information transmission is further improved by encoding the transmitted information. Meanwhile, the invention changes the incident spectrum to ensure that the emergent spectrum received at the same position is also changed continuously, thereby enabling a receiver to obtain changed information continuously. Thus, the transmission of the variable information of the directional fixed point is performed according to the specific position where the receiver is located. Meanwhile, the information transmitted to the receiver is ensured not to be acquired or decoded by an attacker, so that the safety of information transmission is greatly ensured.

The invention aims at the defects of the existing visible light-based information transmission equipment and designs a novel visible polarized light interference-based position-related safety information transmission equipment, which comprises a transmitting end and a receiving end of an optical signal, as shown in figure 1. 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 (e.g., a liquid crystal display), polarized light is emitted, the polarization direction is measured with a linear polarizer, and then a plurality of birefringent materials 3 are fixed to the linear polarizer 2. For the receiving end of the optical signal, a device capable of distinguishing colors is used as the receiver 4 (e.g. camera or photodiode) of the optical signal.

When the security information transmission device is used, polarized light emitted by the emitter is emitted from one end of the birefringent material, the incident light passes through the birefringent material and the linear polarizer and then is emitted from one end of the linear polarizer, and finally, the receiver captures an optical signal and receives specified information.

As shown in fig. 2, the light emitted by the emitter is polarized light, and two polarized light beams L1 and L2 respectively enter into a birefringent material at a point a and a point B, so as to generate a birefringent phenomenon, where L1 is divided into two paths of refracted light of L1o (ordinary light) and L1e (extraordinary light), and L2 is also divided into two paths of refracted light of L2o (ordinary light) and L2e (extraordinary light). As shown, L1e and L2o interfere at point C, and the light after interference is captured by the receiver. Because the light rays are interfered and birefringent, the spectrums generated in different directions and at different distances are different, namely the color information of the light signals received in different positions is different. Because the attacker is different from the position of the receiver, the attacker cannot obtain the correct information of the position of the receiver, and the safety of the invention is ensured.

And when the incident spectrum emitted by the emitter is changed, the emergent spectrum is changed, so that the receiver can continuously receive the changed light information.

For the fabrication of the device, a device capable of emitting light of spectrally variable polarization is used as an emitter, and then a plurality of birefringent materials are fixed to 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 emitter are adjusted. The information is acquired at information receiving points at specified locations using a color-distinguishable device as a receiver. And after receiving the information, carrying out color analysis on each transmitted optical signal.

In summary, the position-related safety information transmission device based on visible polarized light interference in the embodiment of the invention innovatively utilizes the polarization, interference and birefringence characteristics of light to bind the spectrum information of different wavelengths with the information to be transmitted, so that the spectrums received at different positions are different, and the information transmission safety is improved. The device capable of emitting polarized light and changing the incident spectrum is used as an emitter, the birefringent material is used to make incident light incident on the material to generate birefringence, and the device capable of distinguishing colors is used as a receiver.

The invention utilizes the double refraction property and the interference property of polarized light and the physical property of the double refraction material to lead the incident light to be divided into two paths of refraction light after entering the double refraction material, and the refraction light of different incident light rays are interfered after meeting, thereby realizing the transmission of different spectrum information to different positions and solving the technical problem (1). Because the position of the attacker and the appointed receiver are necessarily different, the spectrum obtained by the attacker is necessarily different from the correct spectrum transmitted to the appointed position, and the technical problem (2) is solved. Even if an attacker intercepts an optical signal, the information intercepted by the attacker and the correct information come in and go out due to the deviation of the interception position and the position of the receiver, so that the technical problem (3) is solved. By encoding the color attribute of the optical signal, only the correct code information is transmitted to the appointed receiver, and the error code information with confusion encoded according to the error spectrum information is transmitted to other directions, so that an attacker is difficult to successfully decode, and the technical problem (4) is solved.

While the foregoing description of the embodiments of the present invention has been presented in conjunction with the drawings, it should be understood that it is not intended to limit the scope of the invention, but rather, it should be understood that various changes and modifications could be made by one skilled in the art without the need for inventive faculty, which would fall within the scope of the invention.

Claims (3)

1. A position-dependent security information transmission device based on interference of visible polarized light, comprising: a transmitting end and a receiving end of the optical signal; for the transmitting end of the optical signal, a device capable of emitting polarized light and changing the incident spectrum is used as an emitter for emitting polarized light; measuring the polarization direction by using a linear polarizer, and fixing a plurality of birefringent materials on a linear polarizer; for the receiving end of the optical signal, a device capable of distinguishing colors is used as the receiver of the optical signal.

2. The position-dependent security information transmission apparatus based on interference of visible light according to claim 1, wherein polarized light emitted from the emitter is incident from one end of the birefringent material, and the incident light passes through the birefringent material and the linear polarizer, and then is emitted from one end of the linear polarizer, and finally the optical signal is captured by the receiver to receive the designated information.

3. The position dependent security information transmission apparatus based on interference of visible polarized light according to claim 1, wherein the transmitter emits polarized light of variable spectrum, a plurality of birefringent materials are fixed to the linear polarizer, and positional relationship between the birefringent materials and an angle between their optical axes and the polarized light emitted from the transmitter are adjusted; the device capable of distinguishing colors is used as a receiver, information is acquired at an information receiving point at a designated position, and color analysis is carried out on each transmitted optical signal after the information is received.