Quantum encryption communication system and method, computer equipment and vehicle

Abstract

The invention relates to a quantum encryption communication system and method, computer equipment and a vehicle. The system comprises a transmitting end and a receiving end, wherein the transmitting end comprises a light transmitting device, an external polarization adjusting unit, an internal polarization adjusting unit, a first polarization beam splitter and a second polarization beam splitter. The transmitting terminal can be used for preparing horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light and second orthogonal polarized light, not only can meet quantum communication protocols of four polarization states, but also can meet quantum communication protocols of more than four polarization states. The transmitting end compiles the to-be-transmitted data into a plurality of linearly polarized light and transmits the linearly polarized light to the receiving end through the optical fiber, so that the complexity of transmission coding can be improved, and the communication security is further improved.

Description

Technical Field

[0001] The present application relates to the field of quantum encryption communication technology, and in particular to a quantum encryption communication system, method, computer equipment and vehicle. Background Art

[0002] Traditional confidential communications mainly rely on symmetric encryption and asymmetric encryption, which consume computing resources during the encryption and decryption process, resulting in a decrease in transmission speed. With the rapid development of network technology and communication technology, the amount of communication information has exploded and the complexity of the communication environment has continued to increase. Traditional confidential communications can no longer meet the needs of efficiency and security.

[0003] Compared with traditional secure communication, quantum secure communication uses quantum encryption technology for encoding and transmission. Based on the characteristics of quantum non-copyability, it ensures the security of the transmitted signal and has the potential for instant communication. At present, in quantum secure communication, the transmitting end (also known as Alice) transmits polarized light in four polarization states (such as 0°, 45°, 90°, and 135°) to carry "0" or "1" information. The receiving end (also known as Bob) detects the polarized light through the horizontal and vertical measurement bases and the diagonal measurement bases to obtain the detection results. Alice and Bob can obtain the decrypted message through discussion and comparison.

[0004] In order to improve the complexity and security of quantum encryption, it is necessary to introduce quantum communication protocols with more than 4 polarization states. Obviously, the current transmitter that emits 4 polarization states can no longer meet actual communication and encryption needs. Summary of the invention

[0005] Based on this, it is necessary to provide a quantum encryption communication system, method, computer equipment and vehicle to address the above-mentioned technical problems, which can produce horizontally polarized light, vertically polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light and second orthogonal polarized light to improve communication security.

[0006] In a first aspect, the present application provides a quantum encrypted communication system, the system comprising a transmitting end and a receiving end; the transmitting end comprises a light emitting device, an external polarization adjustment unit, an internal polarization adjustment unit, a first polarization beam splitter, and a second polarization beam splitter;

[0007] The light emitting device is connected to the input end of the first polarization beam splitter through the main optical path; the first output end of the first polarization beam splitter is connected to the first input end of the second polarization beam splitter through the first sub-optical path; the second output end of the first polarization beam splitter is connected to the second input end of the second polarization beam splitter through the second sub-optical path; the output end of the second polarization beam splitter is connected to the receiving end through the optical fiber;

[0008] Wherein, the external polarization adjustment unit is used to adjust the polarization state of the polarized light in the main light path, and is also used to adjust the polarization state of the polarized light output by the second polarization beam splitter;

[0009] The internal polarization adjustment unit is used to adjust the polarization state of the polarized light of the first light sub-path, and is also used to adjust the polarization state of the polarized light of the second light sub-path;

[0010] A transmitting end, used for compiling the data to be transmitted into a plurality of linearly polarized lights, and transmitting the linearly polarized lights to the receiving end through the optical fiber; the linearly polarized lights include at least one of horizontally polarized lights, vertically polarized lights, first diagonally polarized lights, second diagonally polarized lights, first orthogonal polarized lights, and second orthogonal polarized lights;

[0011] The receiving end is used to decode the linearly polarized light to obtain the target data.

[0012] In one embodiment, the external polarization adjustment unit includes a first half-wave plate and a second half-wave plate; the first half-wave plate is arranged on the main optical path, and the second half-wave plate is arranged between the output end of the second polarization beam splitter and the optical fiber.

[0013] In one of the embodiments, the internal polarization adjustment unit includes a third half-wave plate and a fourth half-wave plate; the third half-wave plate is arranged on the first sub-light path, and the fourth half-wave plate is arranged on the second sub-light path.

[0014] In one embodiment, the transmitting end further includes a first reflector and a second reflector; the first reflector is arranged on the first sub-light path, and the second reflector is arranged on the second sub-light path.

[0015] In a second aspect, the present application further provides a quantum encrypted communication method, the method being applied to a transmitting end of a quantum encrypted communication system; the system comprising a transmitting end and a receiving end; the transmitting end comprising a light emitting device, an external polarization adjustment unit, an internal polarization adjustment unit, a first polarization beam splitter, and a second polarization beam splitter;

[0016] The light emitting device is connected to the input end of the first polarization beam splitter through the main optical path; the first output end of the first polarization beam splitter is connected to the first input end of the second polarization beam splitter through the first sub-optical path; the second output end of the first polarization beam splitter is connected to the second input end of the second polarization beam splitter through the second sub-optical path; the output end of the second polarization beam splitter is connected to the receiving end through the optical fiber;

[0017] Wherein, the external polarization adjustment unit is used to adjust the polarization state of the polarized light in the main light path, and is also used to adjust the polarization state of the polarized light output by the second polarization beam splitter;

[0018] The internal polarization adjustment unit is used to adjust the polarization state of the polarized light of the first light sub-path, and is also used to adjust the polarization state of the polarized light of the second light sub-path;

[0019] The method comprises:

[0020] The data to be transmitted is compiled into a plurality of linearly polarized lights, and transmitted to a receiving end through an optical fiber to instruct the receiving end to decode the linearly polarized lights to obtain target data; the linearly polarized lights include at least one of horizontally polarized light, vertically polarized light, first diagonally polarized light, second diagonally polarized light, first orthogonal polarized light, and second orthogonal polarized light.

[0021] In one embodiment, the data to be transmitted is compiled into a plurality of linearly polarized lights, including:

[0022] Convert the data to be transmitted into a binary string;

[0023] Split the binary string into a number of data units; each data unit includes a two-bit character;

[0024] Compile several data units into several linearly polarized lights.

[0025] In one embodiment, a plurality of data units are compiled into a plurality of linearly polarized lights, including:

[0026] Determine a target coding strategy; the target coding strategy defines a mapping relationship between data units and linearly polarized light;

[0027] According to the target coding strategy, several data units are encoded into several linearly polarized lights.

[0028] In one embodiment, the method further comprises:

[0029] A target decoding strategy is agreed upon with the receiving end through negotiation; the receiving end decodes the linearly polarized light based on the target decoding strategy to obtain target data.

[0030] In a third aspect, the present application further provides a computer device, comprising a transmitter or a receiver as described in the first aspect above, and also comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the quantum encryption communication method as described in the second aspect above are implemented.

[0031] In a fourth aspect, the present application further provides a vehicle, comprising the computer device as described in the third aspect above.

[0032] The above-mentioned quantum encrypted communication system, method, computer equipment and vehicle, the transmitting end can prepare horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light and second orthogonal polarized light, which can not only meet the quantum communication protocol of 4 polarization states, but also meet the quantum communication protocol of more than 4 polarization states. The transmitting end compiles the data to be transmitted into several linearly polarized lights and transmits them to the receiving end through optical fiber, which can increase the complexity of transmission coding and thus improve communication security. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] FIG1 is a schematic diagram of quantum key distribution for traditional quantum secure communication;

[0035] FIG2 is a schematic diagram of the structure of a quantum encryption communication system in one embodiment;

[0036] FIG3 is a schematic diagram of the structure of a quantum encryption communication system in another embodiment;

[0037] FIG4 is a schematic diagram of a partial polarizer structure in one embodiment;

[0038] FIG5 is a schematic diagram of the structure of a quantum encryption communication system in another embodiment;

[0039] FIG6 is a schematic flow chart of a quantum encryption communication method in one embodiment;

[0040] FIG7 is a schematic diagram showing a comparison of transmission rates in one embodiment;

[0041] FIG. 8 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0043] It can be understood that, referring to Figure 1, Figure 1 is a schematic diagram of quantum key distribution for traditional quantum secure communication; wherein, the transmitter (Alice) generates polarized light in four polarization states through multiple lasers or a single laser: horizontal polarized light (0°), vertical polarized light (90°), and diagonal polarized light (45° or 135°). The receiver (Bob) detects polarized light through a horizontal vertical measurement basis and a diagonal measurement basis. Referring to Table 1, Table 1 shows a record of a quantum key distribution process, Alice randomly generates a binary string "01011101", prepares polarized light and sends it to Bob; Bob detects the polarized light and determines the detected bit value; Bob informs Alice of the measurement basis used for this detection; Alice informs Bob of which bit values ​​need to be retained; Alice and Bob share the retained key.

[0044] Table 1:

[0045]

[0046] In order to improve the complexity and security of quantum encryption, it is necessary to introduce quantum communication protocols with more than 4 polarization states. Obviously, the current transmitter that emits 4 polarization states can no longer meet actual communication and encryption needs.

[0047] Based on this, the present application provides a quantum encrypted communication system, method, computer equipment and vehicle, the transmitting end can prepare horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light and second orthogonal polarized light, which can not only meet the quantum communication protocol of 4 polarization states, but also meet the quantum communication protocol of more than 4 polarization states. The transmitting end compiles the data to be transmitted into several linearly polarized lights and transmits them to the receiving end through optical fiber, which can increase the complexity of transmission coding and thus improve communication security.

[0048] In an exemplary embodiment, as shown in FIG2 , a quantum encrypted communication system is provided, the system comprising a transmitting end 1 and a receiving end 2; the transmitting end 1 comprises a light emitting device L, an external polarization adjustment unit H1, an internal polarization adjustment unit H2, a first polarization beam splitter PBS1, and a second polarization beam splitter PBS2;

[0049] The light emitting device L is connected to the input end of the first polarization beam splitter PBS1 through the main optical path 3; the first output end of the first polarization beam splitter PBS1 is connected to the first input end of the second polarization beam splitter PBS2 through the first sub-optical path 4; the second output end of the first polarization beam splitter PBS1 is connected to the second input end of the second polarization beam splitter PBS2 through the second sub-optical path 5; the output end of the second polarization beam splitter PBS2 is connected to the receiving end 2 through the optical fiber 6;

[0050] The external polarization adjustment unit H1 is used to adjust the polarization state of the polarized light in the main optical path 3, and is also used to adjust the polarization state of the polarized light output by the second polarization beam splitter PBS2;

[0051] The internal polarization adjustment unit H2 is used to adjust the polarization state of the polarized light of the first light sub-path 4, and is also used to adjust the polarization state of the polarized light of the second light sub-path 5;

[0052] The transmitting end 1 is used to compile the data to be transmitted into a plurality of linear polarized lights and transmit them to the receiving end 2 through the optical fiber 6; the linear polarized lights include at least one of horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light and second orthogonal polarized light;

[0053] The receiving end 2 is used to decode the linearly polarized light to obtain the target data.

[0054] In this embodiment, the light emitting device L may be a laser, which is used to generate linear polarized light of a fixed frequency and transmit it to the first polarization beam splitter PBS1 through the main optical path 3. Optionally, by controlling the light emitting device L, the polarization state of the polarized light output by the light emitting device L can be adjusted; by controlling the light emitting device L and the external polarization adjustment unit H1, the polarization state of the polarized light input to the first polarization beam splitter PBS1 can be adjusted. The external polarization adjustment unit H1 and the internal polarization adjustment unit H2 may be optical devices such as polarizers and wave plates that can change the polarization state.

[0055] It can be understood that the linearly polarized light on the main optical path 3 enters through the input end of the first polarization beam splitter PBS1, and the split linearly polarized lights perpendicular to each other are output through the first output end and the second output end of the first polarization beam splitter PBS1 respectively.

[0056] Among them, by controlling the internal polarization adjustment unit H2, the polarization state of the polarized light of the first sub-optical path 4 and the polarization state of the polarized light of the second sub-optical path 5 can be adjusted. The two beams of linear polarized light adjusted by the internal polarization adjustment unit H2 enter through the first input end and the second input end of the second polarization beam splitter PBS2, and the combined linear polarized light is output through the output end of the second polarization beam splitter PBS2. By controlling the external polarization adjustment unit H1, the polarization state of the polarized light output by the second polarization beam splitter PBS2 can be adjusted.

[0057] In an optional implementation, the first polarization beam splitter PBS1 generates only one linear polarized light by beam splitting, which is transmitted to the second polarization beam splitter PBS2 through the first sub-optical path 4 or the second sub-optical path 5. By controlling the external polarization adjustment unit H1 and the internal polarization adjustment unit H2, different linear polarized lights can be modulated; by beam splitting by the first polarization beam splitter PBS1 and beam combining by the second polarization beam splitter PBS2, orthogonal polarized lights can be generated.

[0058] Exemplarily, the length of the first optical sub-path 4 is the same as the length of the second optical sub-path 5. This embodiment mainly modulates the polarization state of polarized light, uses light of a single wavelength, and does not involve time delay and phase modulation.

[0059] Optionally, the first polarization beam splitter PBS1, the first sub-optical path 4, the second sub-optical path 5, and the second polarization beam splitter PBS2 may adopt the architecture of a Mach-Zehnder interferometer. With the interferometer as the main body, an external polarization adjustment unit H1 is arranged outside the interferometer, and an internal polarization adjustment unit H2 is arranged inside the interferometer. This architecture may be fully optical and use a single wavelength.

[0060] It can be understood that horizontal polarized light is 0° linear polarized light, vertical polarized light is 90° linear polarized light, the first diagonal polarized light is 45° linear polarized light, the second diagonal polarized light is 135° linear polarized light, the first orthogonal polarized light is 0° and 90° linear polarized light, and the second orthogonal polarized light is 45° and 135° linear polarized light.

[0061] In an optional implementation, the polarized light input to the first polarization beam splitter PBS1 is adjusted to horizontal polarized light through an external polarization adjustment unit H1, and is transmitted and output from the first output end of the first polarization beam splitter PBS1. The horizontal polarized light in the first sub-optical path 4 is adjusted to 45° (or 90°) linear polarized light through an internal polarization adjustment unit H2, and the vertical polarized light obtained by splitting the second polarization beam splitter PBS2 is reflected and output from the output end of the second polarization beam splitter PBS2. If the external polarization adjustment unit H1 is controlled to maintain the polarization state of the polarized light output by the second polarization beam splitter PBS2, vertical polarized light is finally output. If the external polarization adjustment unit H1 is controlled to adjust the polarization state of the polarized light output by the second polarization beam splitter PBS2, the first diagonal polarized light or the second diagonal polarized light is finally output.

[0062] The polarized light input to the first polarization beam splitter PBS1 is adjusted to vertical polarized light through the external polarization adjustment unit H1, and is reflected and output from the second output end of the first polarization beam splitter PBS1. The vertical polarized light in the second sub-optical path 5 is adjusted to 45° (or 0°) linear polarized light through the internal polarization adjustment unit H2, and the horizontal polarized light obtained by splitting the second polarization beam splitter PBS2 is transmitted and output from the output end of the second polarization beam splitter PBS2. If the external polarization adjustment unit H1 is controlled to maintain the polarization state of the polarized light output by the second polarization beam splitter PBS2, horizontal polarized light is finally output. If the external polarization adjustment unit H1 is controlled to adjust the polarization state of the polarized light output by the second polarization beam splitter PBS2, the first diagonal polarized light or the second diagonal polarized light is finally output.

[0063] The polarized light input to the first polarization beam splitter PBS1 is adjusted to 45° linear polarized light through the external polarization adjustment unit H1. The first polarization beam splitter PBS1 outputs horizontal polarized light and vertical polarized light. The horizontal polarized light is transmitted and output from the first output end of the first polarization beam splitter PBS1, and the vertical polarized light is reflected and output from the second output end of the first polarization beam splitter PBS1. The horizontal polarized light in the first sub-optical path 4 is adjusted to 45° (or 90°) linear polarized light through the internal polarization adjustment unit H2. The vertical polarized light obtained by splitting through the second polarization beam splitter PBS2 is reflected and output from the output end of the second polarization beam splitter PBS2. The vertical polarized light in the second sub-optical path 5 is adjusted to 45° (or 0°) linear polarized light through the internal polarization adjustment unit H2. The horizontal polarized light obtained by splitting through the second polarization beam splitter PBS2 is transmitted and output from the output end of the second polarization beam splitter PBS2. The second polarization beam splitter PBS2 combines the vertical polarized light and the horizontal polarized light into 0° and 90° linear polarized light. If the external polarization adjustment unit H1 is controlled to maintain the polarization state of the polarized light output by the second polarization beam splitter PBS2, the first orthogonal polarized light is finally output. If the external polarization adjustment unit H1 is controlled to adjust the polarization state of the polarized light output by the second polarization beam splitter PBS2, the second orthogonal polarized light is finally output.

[0064] It can be understood that in this embodiment, the transmitting end 1 compiles the data to be transmitted and generates 6 kinds of linear polarized lights through the polarization state adjustment architecture for transmission in the optical fiber, and the receiving end 2 analyzes and decodes the optical signal to obtain the target data sent by the transmitting end 1.

[0065] Optionally, in the communication transmission, both the transmitter and the receiver are internally controllable. The transmitter 1 only needs to use a fixed-rule encryption code, and the receiver 2 only needs to decode through a fixed-rule detection method. This process does not require the bit comparison link of quantum encryption technology to complete the decoding, and the decoding process does not require any computing power resources to encrypt and decrypt. Assume that the length of the binary string of the data to be transmitted is n, each linear polarization light carries a two-bit character, and the receiver uses a 2-choice 1 detection method, with a total of 1 / (2 n / 2 ) ways; the transmitter uses a 6-choose-4 encoding method, with a total of 1 / 15 ways. If there is an eavesdropper during the transmission process, due to the principle that quantum has a superposition state and cannot be copied, the transmitted code has only one chance to be decrypted by the eavesdropper. Without considering complex situations, the highest probability of decryption is only 1 / (15*2 n / 2 ), and the encryption process also contains two fuzzy parameters, so it is actually impossible to obtain the transmitted information through eavesdropping, and the communication security is extremely high.

[0066] In the above quantum encrypted communication system, the transmitter can prepare horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light, and second orthogonal polarized light, which can not only meet the quantum communication protocol of 4 polarization states, but also meet the quantum communication protocol of more than 4 polarization states. The transmitter compiles the data to be transmitted into several linearly polarized lights and transmits them to the receiver through optical fiber, which can increase the complexity of transmission coding and thus improve communication security.

[0067] In an exemplary embodiment, as shown in FIG. 3 , the external polarization adjustment unit H1 includes a first half-wave plate H F and the second half-wave plate H B ; The first half-wave plate H F Set on the main optical path 3, the second half-wave plate H B It is arranged between the output end of the second polarization beam splitter and the optical fiber 6.

[0068] Among them, the half-wave plate is also called a half-wave plate. By controlling the vibration plane of the incident light and the first half-wave plate H F The angle between the crystal optical axes can adjust the polarization state of the polarized light input to the first polarization beam splitter PBS1. B The angle between the crystal optical axes can adjust the polarization state of the polarized light output by the second polarization beam splitter PBS2.

[0069] In an exemplary embodiment, as shown in FIG. 3 , the internal polarization adjustment unit H2 includes a third half-wave plate H P and the fourth half-wave plate H S ; The third half-wave plate H P Set on the first sub-optical path 4, the fourth half-wave plate H S Set on the second sub-optical path 5.

[0070] By controlling the vibration plane of the incident light and the third half-wave plate H P The angle between the crystal optical axes can adjust the polarization state of the polarized light of the first sub-light path 4. By controlling the incident light vibration plane and the fourth half-wave plate H S The angle between the crystal optical axes can adjust the polarization state of the polarized light in the second sub-optical path 5 .

[0071] In an exemplary embodiment, as shown in FIG. 3 , the transmitting end 1 further includes a first reflector M1 and a second reflector M2 ; the first reflector M1 is disposed on the first sub-optical path 4 , and the second reflector M2 is disposed on the second sub-optical path 5 .

[0072] Among them, the first reflector M1 and the second reflector M2 are used to guide the transmission path of the light beam. In the first sub-optical path 4 and the second sub-optical path 5, the light beam is reflected in the set direction by the reflector to ensure that the light beam is accurately transmitted and reduce the energy loss of the light beam during the transmission process.

[0073] In an optional implementation, referring to FIG. 3 , a first half-wave plate H F , adjust the polarized light input to the first polarization beam splitter PBS1 to horizontal polarization light, and transmit it out from the first output end of the first polarization beam splitter PBS1. P The horizontal polarized light in the first optical sub-path 4 is adjusted to 45° (or 90°) linear polarized light, and the vertical polarized light obtained by the second polarization beam splitter PBS2 is reflected and output from the output end of the second polarization beam splitter PBS2. B The polarization state of the polarized light output by the second polarization beam splitter PBS2 is maintained, and vertical polarized light is finally output. B The polarization state of the polarized light output by the second polarization beam splitter PBS2 is adjusted, and the first diagonal polarized light or the second diagonal polarized light is finally output.

[0074] Through the first half-wave plate H F , adjust the polarized light input to the first polarization beam splitter PBS1 to vertical polarization light, and reflect and output from the second output end of the first polarization beam splitter PBS1. S The vertical polarized light in the second optical sub-path 5 is adjusted to 45° (or 0°) linear polarized light, and the horizontal polarized light obtained by the second polarization beam splitter PBS2 is transmitted and output from the output end of the second polarization beam splitter PBS2. B The polarization state of the polarized light output by the second polarization beam splitter PBS2 is maintained, and finally horizontal polarized light is output. B The polarization state of the polarized light output by the second polarization beam splitter PBS2 is adjusted, and the first diagonal polarized light or the second diagonal polarized light is finally output.

[0075] Through the first half-wave plate H F , adjust the polarized light input to the first polarization beam splitter PBS1 to 45° linear polarized light, the first polarization beam splitter PBS1 outputs horizontal polarized light and vertical polarized light, the horizontal polarized light is transmitted and output from the first output end of the first polarization beam splitter PBS1, and the vertical polarized light is reflected and output from the second output end of the first polarization beam splitter PBS1. PThe horizontal polarized light in the first optical sub-path 4 is adjusted to 45° (or 90°) linear polarized light, and the vertical polarized light is reflected and output from the output end of the second polarization beam splitter PBS2 after being split by the second polarization beam splitter PBS2. S The vertical polarized light in the second optical sub-path 5 is adjusted to 45° (or 0°) linear polarized light, and the horizontal polarized light obtained by splitting the second polarization beam splitter PBS2 is transmitted and output from the output end of the second polarization beam splitter PBS2. The second polarization beam splitter PBS2 combines the vertical polarized light and the horizontal polarized light into 0° and 90° linear polarized light. If the second half-wave plate H is controlled B The polarization state of the polarized light output by the second polarization beam splitter PBS2 is maintained, and finally the first orthogonal polarized light is output. B The polarization state of the polarized light output by the second polarization beam splitter PBS2 is adjusted, and a second orthogonal polarized light is finally output.

[0076] It is understandable that in order to verify the feasibility of the transmitter architecture in the communication system of quantum encryption, the partial polarizer architecture is first described. Referring to FIG. 4 , FIG. 4 is a schematic diagram of a partial polarizer architecture in an embodiment; the partial polarizer is a polarizer architecture with linear double attenuation (Linear Diattenuation, LD), the basic architecture is a Mach-Zehnder interferometer, and a half-wave plate H is set on the optical path of FIG. 4 (a) and the optical path of FIG. 4 (b). P and H S The incident light vibration plane and the half-wave plate H P The angle between the crystal optical axes is θ, and the incident light vibration plane is angular with the half-wave plate H. S The angle between the crystal optical axes is (θ+45°). After Jones matrix calculation, the Jones matrix of the Mach-Zehnder interferometer is:

[0077] ;

[0078] ;

[0079] .

[0080] Add half-wave plates H before and after the structure shown in Figure 4 F and H B , the incident light vibration plane and the half-wave plate H P The angle between the crystal optical axes is α, and the incident light vibration plane is angular with the half-wave plate H. S The angle between the crystal optical axes is also α. After the Jones matrix operation, the Jones matrix of the structure after adding the half-wave plate can be obtained. After comparing the Jones matrix of the partial polarizer, it is known that the transmitting end structure of the present application can be used as a partial polarizer.

[0081] Among them, the Jones matrix of some polarizers is:

[0082] ;

[0083] The Jones matrix of the transmitting end architecture of this application is:

[0084] ;

[0085] The similarity is:

[0086] ;

[0087] ;

[0088] The Jones matrix of the transmitting end architecture of the present application is converted into a Mueller matrix, specifically:

[0089] ;

[0090] The polarizer Mueller matrix is:

[0091] ;

[0092] By comparison, it can be known that the transmitting end architecture of the present application can be used as a polarizer calibration system with linear attenuation.

[0093] Based on the characteristics of linear double attenuation (LD), different linear attenuation LD and penetration axis will produce different results. Under specific conditions, this architecture can produce 6 types of linear polarized light that can be used for quantum encryption, namely: LD=1, 0° linear polarized light; LD=1, 90° linear polarized light; LD=1, 45° linear polarized light; LD=1, 135° linear polarized light; LD=0.707, 0° and 90° linear polarized light; LD=0.707, 45° and 135° linear polarized light.

[0094] In an optional implementation, referring to Figure 5, the receiving end 2 includes a selection module, a rotator R (rotator), a third polarization beam splitter PBS3, and a fourth polarization beam splitter PBS4; it also includes a linear detector 7 connected to the third polarization beam splitter PBS3, and a diagonal detector 8 connected to the fourth polarization beam splitter PBS4.

[0095] In an exemplary embodiment, as shown in FIG6 , a quantum encryption communication method is provided, the method being applied to a transmitting end of a quantum encryption communication system; the system comprises a transmitting end and a receiving end; the transmitting end comprises a light emitting device, an external polarization adjustment unit, an internal polarization adjustment unit, a first polarization beam splitter, and a second polarization beam splitter;

[0096] The light emitting device is connected to the input end of the first polarization beam splitter through the main optical path; the first output end of the first polarization beam splitter is connected to the first input end of the second polarization beam splitter through the first sub-optical path; the second output end of the first polarization beam splitter is connected to the second input end of the second polarization beam splitter through the second sub-optical path; the output end of the second polarization beam splitter is connected to the receiving end through the optical fiber;

[0097] Wherein, the external polarization adjustment unit is used to adjust the polarization state of the polarized light in the main light path, and is also used to adjust the polarization state of the polarized light output by the second polarization beam splitter;

[0098] The internal polarization adjustment unit is used to adjust the polarization state of the polarized light of the first light sub-path, and is also used to adjust the polarization state of the polarized light of the second light sub-path;

[0099] The method comprises:

[0100] Step S602, compile the data to be transmitted into a plurality of linear polarized lights, and transmit them to the receiving end through the optical fiber to instruct the receiving end to decode the linear polarized lights to obtain the target data; the linear polarized light includes at least one of horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light and second orthogonal polarized light.

[0101] It can be understood that the implementation solution to the problem provided by the present method is similar to the implementation solution recorded in the above-mentioned system. Therefore, the specific limitations on the transmitting end in one or more quantum encryption communication method embodiments provided below can refer to the limitations on the quantum encryption communication system above, and will not be repeated here.

[0102] In the above-mentioned quantum encryption communication method, the transmitter can prepare horizontal polarized light, vertical polarized light, first diagonal polarized light, second diagonal polarized light, first orthogonal polarized light, and second orthogonal polarized light, which can not only meet the quantum communication protocol of 4 polarization states, but also meet the quantum communication protocol of more than 4 polarization states. The transmitter compiles the data to be transmitted into several linearly polarized lights and transmits them to the receiving end through optical fiber, which can increase the complexity of transmission coding and thus improve communication security.

[0103] In an exemplary embodiment, compiling the data to be transmitted into a plurality of linearly polarized lights includes: converting the data to be transmitted into a binary string; splitting the binary string into a plurality of data units; each data unit includes a two-bit character; and compiling the plurality of data units into a plurality of linearly polarized lights.

[0104] It can be understood that, with reference to FIG. 7 , FIG. 7 is a comparative diagram of the transmission rate in one embodiment; currently, the transmission data generally uses binary bits as the basis for data transmission. In certain specific scenarios, the requirements for data transmission rate are extremely high, for example, the data transmission of electronic rearview mirrors in vehicle communications. In traditional quantum secure communications, each linearly polarized light carries a single-bit character. In the embodiments of the present application, by expanding the types of linearly polarized light at the transmitting end and agreeing that each linearly polarized light carries two-bit characters, the number of bits transmitted per second is increased, thereby increasing the data transmission rate and reducing the transmission delay. Similarly, the receiving end can obtain more characters by analyzing the linearly polarized light, thereby increasing the data processing rate.

[0105] In this embodiment, the signal transmitted by the transmitter can transmit two bits of characters at a time, which can increase the data transmission rate by 4 times or more compared to the two-way serial communication, and has the advantage of being impossible to be deciphered. It can be applied to the field of automotive communication that requires confidentiality and fast transmission, such as real-time image transmission of HUD (head-up display), image transmission of electronic rearview mirror, and image transmission of real-time reversing image.

[0106] In an exemplary embodiment, compiling a plurality of data units into a plurality of linearly polarized lights includes: determining a target coding strategy; the target coding strategy defines a mapping relationship between data units and linearly polarized lights; and compiling a plurality of data units into a plurality of linearly polarized lights according to the target coding strategy.

[0107] The transmitting end and the receiving end pre-agreed on a fixed and mutually matching target encoding strategy and target decoding strategy. It is understandable that the transmitting end and the receiving end do not expose the encoding strategy and decoding strategy used to the outside.

[0108] Exemplarily, referring to Table 2, Table 2 shows a mapping relationship between a data unit and linear polarized light; wherein, the transmitting end is set to encode "10" and "01" based on the first orthogonal polarized light and the second orthogonal polarized light, and is set to encode "11" and "00" based on horizontal polarized light, vertical polarized light, first diagonal polarized light, and second diagonal polarized light.

[0109] Table 2:

[0110]

[0111] Based on Table 2, for the binary string "01001011", the transmitter compiles: first orthogonal polarized light, first diagonal polarized light, second orthogonal polarized light, horizontal polarized light.

[0112] In an optional implementation, a fleet includes multiple vehicles, each vehicle is provided with a transmitter and a receiver connected by optical fiber, and each vehicle is provided with a vehicle identification for distinguishing the identity of the vehicle. Each vehicle in the fleet manages multiple coding strategies, and can distinguish the coding strategies corresponding to different strategy identifications. In a specific implementation, after any vehicle in the fleet selects a coding strategy, it passes the corresponding strategy identification to other vehicles in the fleet. When the current vehicle selects a coding strategy, it first obtains the strategy identification selected by other vehicles in the fleet, excludes the coding strategy corresponding to the strategy identification from the multiple supported coding strategies, and selects the corresponding coding strategy from the remaining coding strategies. In this way, it is ensured that the coding strategies of each vehicle in the fleet are different, thereby improving the communication security of the fleet.

[0113] In an exemplary embodiment, the method further includes: negotiating with the receiving end to agree on a target decoding strategy with the receiving end; the receiving end decodes the linearly polarized light based on the target decoding strategy to obtain target data.

[0114] Among them, the receiving end manages multiple decoding strategies, which correspond to the encoding strategies of the transmitting end, and the receiving end can distinguish the decoding strategies corresponding to different strategy identifiers. The transmitting end negotiates with the receiving end and provides the strategy identifier to the receiving end. The receiving end can determine the target decoding strategy corresponding to the strategy identifier based on the strategy identifier. When linearly polarized light is subsequently received, the linearly polarized light emitted by the transmitting end is decoded based on the target decoding strategy to obtain the data transmitted by the transmitting end.

[0115] It should be understood that, unless otherwise clearly stated herein, the execution of the steps of the methods involved in the above-mentioned embodiments is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps involved in the above-mentioned embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the steps or stages in other steps.

[0116] In an exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be shown in FIG8. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a quantum encryption communication method is implemented.

[0117] Those skilled in the art will understand that the structure shown in FIG. 8 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0118] In an exemplary embodiment, a computer device is provided, which includes a transmitter or a receiver provided in any embodiment of the present application, and also includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the quantum encryption communication method provided in any embodiment of the present application are implemented.

[0119] In one embodiment, a vehicle is provided, wherein the vehicle includes a computer device as provided in any one of the embodiments of the present application.

[0120] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0121] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0122] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0123] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A quantum encrypted communication system, characterized in that: The system comprises a transmitting end and a receiving end; the transmitting end comprises a light emitting device, an external polarization adjustment unit, an internal polarization adjustment unit, a first polarization beam splitter and a second polarization beam splitter; The light emitting device is connected to the input end of the first polarization beam splitter through a main optical path; the first output end of the first polarization beam splitter is connected to the first input end of the second polarization beam splitter through a first sub-optical path; the second output end of the first polarization beam splitter is connected to the second input end of the second polarization beam splitter through a second sub-optical path; the output end of the second polarization beam splitter is connected to the receiving end through an optical fiber; Wherein, the external polarization adjustment unit is used to adjust the polarization state of the polarized light in the main optical path, and is also used to adjust the polarization state of the polarized light output by the second polarization beam splitter; The internal polarization adjustment unit is used to adjust the polarization state of the polarized light of the first light sub-path, and is also used to adjust the polarization state of the polarized light of the second light sub-path; The transmitting end is used to compile the data to be transmitted into a plurality of linearly polarized lights, and transmit the linearly polarized lights to the receiving end through the optical fiber; the linearly polarized lights include at least one of horizontally polarized lights, vertically polarized lights, first diagonally polarized lights, second diagonally polarized lights, first orthogonal polarized lights, and second orthogonal polarized lights; The receiving end is used to decode the linearly polarized light to obtain target data.

2. The system according to claim 1, characterized in that The external polarization adjustment unit includes a first half-wave plate and a second half-wave plate; the first half-wave plate is arranged on the main optical path, and the second half-wave plate is arranged between the output end of the second polarization beam splitter and the optical fiber.

3. The system according to claim 1, characterized in that The internal polarization adjustment unit includes a third half-wave plate and a fourth half-wave plate; the third half-wave plate is arranged on the first sub-light path, and the fourth half-wave plate is arranged on the second sub-light path.

4. The system according to claim 1, characterized in that The transmitting end further includes a first reflector and a second reflector; the first reflector is arranged on the first sub-optical path, and the second reflector is arranged on the second sub-optical path.

5. A quantum encrypted communication method, characterized in that: The method is applied to a transmitting end of a quantum encrypted communication system; the system comprises a transmitting end and a receiving end; the transmitting end comprises a light emitting device, an external polarization adjustment unit, an internal polarization adjustment unit, a first polarization beam splitter and a second polarization beam splitter; The light emitting device is connected to the input end of the first polarization beam splitter through a main optical path; the first output end of the first polarization beam splitter is connected to the first input end of the second polarization beam splitter through a first sub-optical path; the second output end of the first polarization beam splitter is connected to the second input end of the second polarization beam splitter through a second sub-optical path; the output end of the second polarization beam splitter is connected to the receiving end through an optical fiber; Wherein, the external polarization adjustment unit is used to adjust the polarization state of the polarized light in the main optical path, and is also used to adjust the polarization state of the polarized light output by the second polarization beam splitter; The internal polarization adjustment unit is used to adjust the polarization state of the polarized light of the first light sub-path, and is also used to adjust the polarization state of the polarized light of the second light sub-path; The method comprises: The data to be transmitted is compiled into a plurality of linearly polarized lights, and transmitted to the receiving end through an optical fiber to instruct the receiving end to decode the linearly polarized lights to obtain target data; the linearly polarized lights include at least one of horizontally polarized light, vertically polarized light, first diagonally polarized light, second diagonally polarized light, first orthogonal polarized light, and second orthogonal polarized light.

6. The method according to claim 5, characterized in that The step of compiling the data to be transmitted into a plurality of linearly polarized lights comprises: Convert the data to be transmitted into a binary string; Splitting the binary string into a plurality of data units; each data unit includes a two-bit character; The plurality of data units are compiled into a plurality of linearly polarized lights.

7. The method according to claim 6, characterized in that The compiling the plurality of data units into a plurality of linearly polarized lights comprises: Determining a target coding strategy; the target coding strategy defines a mapping relationship between data units and linearly polarized light; According to the target coding strategy, the plurality of data units are encoded into a plurality of linearly polarized lights.

8. The method according to claim 5, characterized in that The method further comprises: A target decoding strategy is agreed upon with the receiving end through negotiation; the receiving end decodes the linearly polarized light based on the target decoding strategy to obtain target data.

9. A computer device, characterized in that: The computer device comprises a transmitter or a receiver as described in any one of claims 1 to 4, and the computer device further comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method described in any one of claims 5 to 8 when executing the computer program.

10. A vehicle, characterized in that: The vehicle comprises the computer device of claim 9.

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