Information transmission method and electronic device for quantum communication perception

Abstract

The present application proposes a quantum communication-aware information transmission method, an electronic device, and a computer-readable storage medium, wherein the information transmission method comprises generating a first photon sequence in response to a quantum communication perception instruction; using the first photon sequence to perform a first encoding on the information bits to be transmitted, generating a photon sequence with a first quantum state; performing a second encoding on the sensing parameters to be transmitted, generating a photon sequence with a second quantum state; and sending the photon sequence with the second quantum state to a receiver through a quantum direct communication system. According to an embodiment of the present application, sensing parameters and quantum direct communication are realized using photons, thereby improving the security of communication perception integration.

Description

Technical Field

[0001] The present application relates to the field of quantum direct communication, and in particular, to a quantum communication-aware information transmission method, electronic device, and computer-readable storage medium. Background Art

[0002] Based on the basic principles of quantum mechanics, quantum communication provides security for information exchange. Relying on quantum entanglement and using it as a core resource, a variety of quantum communication paradigms with information-theoretic security have been established, including quantum key distribution (QKD) and quantum secure direct communication (QSDC). Quantum direct communication can safely and reliably transmit information in quantum channels that are susceptible to eavesdropping and noise, and has the characteristics of high security capacity.

[0003] Recently, with the further research and standardization of 6G technology, the entire communication network can act as a huge sensor to send and receive signals, which can more efficiently utilize resources and improve system performance to meet the needs of scenarios such as intelligent interaction, high-precision positioning, and autonomous driving.

[0004] However, although the existing technology uses integrated sensing and communication (ISAC) of classical channels to integrate communication and perception capabilities into the same system, its security cannot be guaranteed.

[0005] The inventors of this application have discovered that the prior art does not yet have a technical solution that uses quantum direct communication to achieve integrated communication and perception. However, integrating quantum technology with communication and perception can significantly improve communication security and measurement accuracy. Summary of the invention

[0006] The present application aims to propose a method for information transmission of quantum communication perception, an electronic device and a computer-readable storage medium to solve the problem of how to achieve quantum perception integration while performing quantum direct communication.

[0007] According to one aspect of the present application, a method for information transmission based on quantum communication is proposed, comprising: generating a first photon sequence in response to a quantum communication perception instruction; performing a first encoding on information bits to be transmitted using the first photon sequence to generate a photon sequence with a first quantum state; performing a second encoding on sensing parameters to be transmitted to generate a photon sequence with a second quantum state; and sending the photon sequence with the second quantum state to a receiver through a quantum direct communication system.

[0008] According to some embodiments, before sending the photon sequence having the second quantum state to a receiver through a quantum direct communication system, it also includes: generating an entangled photon sequence having the same quantum state as the first photon sequence to obtain a second photon sequence; and using the second photon sequence to detect the channel security of the quantum direct communication system.

[0009] According to some embodiments, the first photon sequence is used to perform a first encoding on the information bits to be transmitted to generate a photon sequence with a first quantum state, including: according to a preset correspondence between the first quantum state and the information bits, the first photon sequence is used to perform a first encoding on the information bits to be transmitted to generate photons with a first quantum state.

[0010] According to some embodiments, using the first photon sequence to perform a first encoding on the information bits to be transmitted to generate a photon sequence with a first quantum state includes: using the first photon sequence to perform a first unitary operation on the information bits to be transmitted to generate a photon sequence with the first quantum state.

[0011] According to some embodiments, the first unitary operation is expressed as follows:

[0012] U 0 =I=|0><0|+|1><1|, U 1 =σ x =|0><1|+|1><0|, where I is the identity matrix, σ x is the Pauli x matrix, U 0 Indicates mapping the information bit 0 to the first quantum state, U 1 It means that the information bit 1 is mapped to the first quantum state, |0> and |1> indicate that the photon is in the horizontal and vertical polarization states respectively, <0| is the conjugate transpose of |0>, and <1| is the conjugate transpose of |1>.

[0013] According to some embodiments, the sensing parameters include phase information, and performing a second encoding on the sensing parameters to be transmitted to generate a photon sequence with a second quantum state includes: performing a second unitary operation on the sensing parameters to be transmitted to generate a photon sequence with a second quantum state.

[0014] According to some embodiments, the second unitary operation is expressed as follows:

[0015] U θ =|0><0|+e iθ |1><1|

[0016] Among them, U θ is the second unitary operation, |0> and |1> represent the photon in horizontal and vertical polarization states respectively, and θ is the sensing parameter.

[0017] According to some embodiments, the information transmission method further comprises: performing disordered encoding on the first photon sequence for eavesdropping detection on the quantum direct communication system.

[0018] According to one aspect of the present application, a method for information transmission based on quantum communication is proposed, comprising: receiving a photon sequence with a second quantum state sent from a sender; decoding the photon sequence with the second quantum state to obtain transmission information; and estimating a transmission sensing parameter based on the quantity distribution of the transmission information.

[0019] According to some embodiments, decoding the second quantum state to obtain transmission information includes: decoding the second quantum state using a preset measurement operator to obtain transmission information.

[0020] According to some embodiments, the sensing parameters include phase information, and the transmitted sensing parameters are estimated based on the quantity distribution of the transmitted information, including: calculating the expected value of the measurement operator based on the quantity distribution of the detector response corresponding to the measurement operator; and estimating the phase information based on the expected value.

[0021] According to some embodiments, the measurement operator is as follows:

[0022]

[0023] According to one aspect of the present application, an electronic device is proposed, comprising: a processor; and a memory storing a computer program, wherein when the computer program is executed by the processor, the processor executes the editing method as described in any of the previous embodiments.

[0024] According to one aspect of the present application, a non-transitory computer-readable storage medium is provided, on which computer-readable instructions are stored. When the instructions are executed by a processor, the processor executes the editing method as described in any of the previous embodiments.

[0025] According to the embodiments of the present application, sensing parameters and quantum direct communication are realized by using photons, thereby improving the security of communication and perception integration.

[0026] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. By describing the exemplary embodiments in detail with reference to the drawings, the above and other objectives, features and advantages of the present application will become more apparent.

[0028] Figure 1 A flow chart of an information transmission method based on quantum communication according to an exemplary embodiment of the present application is shown.

[0029] Figure 2 A flow chart of another information transmission method based on quantum communication according to an exemplary embodiment of the present application is shown.

[0030] Figure 3 A schematic diagram showing the eigenvalues ​​corresponding to each detector according to an exemplary embodiment of the present application is shown.

[0031] Figure 4 A schematic diagram of photon sequence changes during information transmission based on quantum communication according to an exemplary embodiment of the present application is shown.

[0032] Figure 5 A schematic diagram of an information transmission structure based on quantum communication according to an exemplary embodiment of the present application is shown.

[0033] Figure 6 A flow chart of an information transmission method based on quantum communication according to an exemplary embodiment of the present application is shown.

[0034] Figure 7 A schematic diagram of a safety capacity curve according to an exemplary embodiment of the present application is shown.

[0035] Figure 8 A schematic diagram of a Fisher information reference curve according to an exemplary embodiment of the present application is shown.

[0036] Fig. 9 An electronic device according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0037] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0038] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices or operations may be adopted. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0039] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0040] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0041] The specific embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0042] Figure 1 A flow chart of an information transmission method based on quantum communication according to an exemplary embodiment of the present application is shown, wherein Figure 1 The method shown is used for the sending end of quantum direct communication. Figure 1 As shown, Figure 1 The method shown includes steps S101 , S103 , S105 and S107 .

[0043] In step S101, in response to a quantum communication sensing instruction, a first photon sequence is generated.

[0044] According to an embodiment of the present application, before using a photon sequence for quantum direct communication, it is also necessary to detect the channel security of the quantum direct communication.

[0045] In a specific embodiment, for example, in step S101, an entangled photon sequence having the same quantum state as the first photon sequence is generated to obtain a second photon sequence, wherein the first photon sequence is used to transmit data, and the second photon sequence is used to detect the channel security of quantum direct communication.

[0046] In step S103, the first photon sequence is used to perform a first encoding on the information bits to be transmitted, so as to generate a photon sequence having a first quantum state.

[0047] According to some embodiments, before step S103, in order to reduce the bit error rate of information transmission, it is necessary to delete the photons involved in detecting channel security from the first photon sequence.

[0048] According to an embodiment of the present application, in step S103, according to the preset corresponding relationship between the first quantum state and the information bit, the information bit to be transmitted is first encoded using the first photon sequence to generate a photon sequence with the first quantum state.

[0049] In a specific embodiment, a first unitary operation is performed on information bits to be transmitted using a first photon sequence to generate a photon sequence having the first quantum state.

[0050] Specifically, the first unitary operation includes formula (1) and formula (2). According to formula (2), the -00+11 state is used to represent information bit 1; according to formula (1), the 01-10 state is used to represent information bit 0.

[0051] U 0 =I=|0><0|+|1><1| (1)

[0052] U 1 =σ x =|0><1|+|1><0| (2)

[0053] Where I is the identity matrix, σ x is the Pauli x matrix, U 0 Indicates mapping the information bit 0 to the first quantum state, U 1 It means that the information bit 1 is mapped to the first quantum state, |0> and |1> indicate that the photon is in the horizontal and vertical polarization states respectively, <0| is the conjugate transpose of |0>, and <1| is the conjugate transpose of |1>.

[0054] In step S105, the sensing parameters to be transmitted are second encoded to generate a photon sequence with a second quantum state.

[0055] Since most physical quantities that need to be precisely measured (for example, electromagnetic field strength, weak inertial force and time frequency standard) can be projected onto the phase, and these phases can be inferred and estimated using an interferometer. Since there is no Hermitian operator corresponding to the phase, it cannot be directly measured experimentally and can only be obtained by estimation. Therefore, phase estimation becomes an important part of quantum sensing. The estimated phase can be used for seismic wave detection, detecting the relative phase position of both parties or non-zero magnetic field, high-dimensional detectors, etc. According to an embodiment of the present application, the sensing parameters include the phase information of the collected physical quantities, including but not limited to electromagnetic field strength, weak inertial force and / or time frequency standard.

[0056] According to an embodiment of the present application, in step S105, a second unitary operation is performed on the sensing parameter to be transmitted to generate a photon sequence having a second quantum state.

[0057] In a specific embodiment, the second unitary operation is shown in formula (3).

[0058] U θ =|0><0|+e iθ |1><1| (3)

[0059] Where θ is the phase information of the photon in the first quantum state involved in information encoding. |0> is the horizontal polarization state of the photon, and <0| is the conjugate transpose of |0>.

[0060] In step S107, the photon sequence having the second quantum state is sent to a receiver via a quantum direct communication system.

[0061] According to an embodiment of the present application, before step S107, in order to prevent eavesdropping, Figure 1 The method shown also includes randomly encoding the first photon sequence for eavesdropping detection of the quantum direct communication system.

[0062] In a specific embodiment, first, a photon is randomly selected from the first photon sequence; and a third unitary operation is performed on the selected photon; then, the selected photon information and the third unitary operation information are sent to the receiver so that the receiver performs Bell state measurement; finally, the receiver calculates the bit error rate based on the measurement result of the Bell state measurement to perform eavesdropping detection on the quantum direct communication system.

[0063] In some embodiments, the photons participating in the encoding in step S103 are photons participating in the disordered encoding that are deleted.

[0064] according to Figure 1 The illustrated embodiment utilizes photons to realize sensing parameters and quantum direct communication, thereby improving the security of communication and perception integration.

[0065] Figure 2 A flowchart of another information transmission method based on quantum communication according to an exemplary embodiment of the present application is shown, wherein Figure 2 The method shown is used for the receiving end of quantum direct communication. Figure 2 As shown, Figure 2 The method shown includes steps S201, S203 and step S205.

[0066] In step S201, a photon sequence having a second quantum state is received from a sender.

[0067] and Figure 1 Correspondingly, what is received in step S201 is a photon sequence having a second quantum state that has been secondarily encoded.

[0068] In step S203, the photon sequence having the second quantum state is decoded to obtain transmission information.

[0069] In a specific embodiment, the second quantum state is decoded using a preset measurement operator to obtain the transmission information, wherein the measurement operator is shown in formula (4) and formula (5).

[0070]

[0071]

[0072] Here, i is an imaginary number.

[0073] In the embodiment of the present application, the measurement operators shown in formulas (4) and (5) each have four eigenvectors corresponding to four detectors, where: The four eigenvectors of are shown in formula (6), The four eigenvectors of are shown in formula (7).

[0074] |t 1 >=-|00>+|11>,

[0075] |t 2 >=|00>+|11>,

[0076] |t 3 >=|01>+|10>,

[0077] |t 4 >=-|01>+|10> (6)

[0078] |r 1 >=i|00>+|11>,

[0079] |r 2 >=-i|00>+|11>,

[0080] |r 3 >=i|01>+|10>,

[0081] |r 4 >=-i|01>+|10> (7)

[0082] According to formulas (1) and (2), referring to the preset correspondence between the first quantum state and the information bit, when |t 1 > and |t 2 > or |r 1 > and |r 2 >When the corresponding detector responds, the corresponding information bit is 1. When |t 3 > and |t 4 > or |r 3 > and |r 4 >When the corresponding detector responds, the corresponding information bit is 0.

[0083] In step S205, the transmitted sensing parameters are estimated according to the quantity distribution of the transmitted information.

[0084] According to an embodiment of the present application, in step S205, first, the expected value of the measurement operator is calculated according to the quantitative distribution of the detector response corresponding to the measurement operator, as shown in formula (8); then, the phase information is estimated according to the expected value, as shown in formula (9).

[0085] In a specific embodiment, the actual expected value of the measurement operator is obtained by calculating the number of detector responses, as shown in formula (8).

[0086]

[0087] Among them, x i and p i are the eigenvalue and response ratio corresponding to the i-th detector respectively. The eigenvalue corresponding to each detector is as follows Figure 3 shown.

[0088]

[0089]

[0090] Wherein, N is the number of encoding times of the sensing parameters.

[0091] according to Figure 2 The illustrated embodiment realizes the decoding of transmitted information and sensing parameters, and implements quantum secure communication.

[0092] Figure 4 FIG. 1 is a schematic diagram showing a photon sequence change during information transmission based on quantum communication according to an exemplary embodiment of the present application. Figure 4 The quantum communication shown includes information sender Alice and information receiver Bob.

[0093] First, two initially distributed entangled photon sequences are generated at Alice's end, including column A and column B, and column B is sent to Bob.

[0094] Afterwards, both parties select particles for eavesdropping detection and then throw them away, such as Figure 4 The circles shown change to dashed photons.

[0095] Afterwards, Alice encodes the A sequence photons and the information data and sensing parameters to be transmitted twice, such as Figure 4 As shown in , the photons represented by circles are changed into pentagons and rhombuses. Then photons are randomly selected for disordered encoding, such as Figure 4 As indicated by the arrow in .

[0096] Afterwards, the encoded sequence A is sent to Bob, who uses the circle shown in the arrow for eavesdropping detection and then throws it away, turning it into a dotted circle.

[0097] Figure 5 A schematic diagram of an information transmission structure based on quantum communication according to an exemplary embodiment of the present application is shown. Figure 5 The quantum communication shown includes an information transmitter Alice and an information receiver Bob, wherein Alice is used to prepare, distribute, and encode entangled photons, and Bob is used to receive, decode, and phase-aware entangled photons.

[0098] First, the information sender Alice and the information receiver Bob predetermine the correspondence between quantum states and information bits.

[0099] In a specific embodiment, Alice and Bob agree in advance that the 01-10 state represents information bit 0, and the -00+11 state represents information bit 1. Then, Alice encodes the initial quantum state of the photon into the 01-10 state and the -00+11 state, respectively, so that during the decoding process, Bob can determine whether the transmitted information bit is 0 or 1 according to whether the quantum state is 01-10 or -00+11.

[0100] Afterwards, Alice generates a series of entangled photons with the same quantum state, recorded as sequence A and sequence B, and distributes sequence B to Bob to detect whether the quantum communication channel is secure.

[0101] In a specific embodiment, after Bob receives the photon sequence, Alice and Bob conduct the first eavesdropping test. Bob randomly selects some photons from sequence B and randomly performs Pauli σ x , σ y , σ z Then Bob notifies Alice of the selected photon positions and the measurement basis used. Alice uses the same basis to measure the photons corresponding to these photons in sequence A and obtains the opposite result to Bob. That is, assuming that the quantum states initially distributed are 01-10, if Bob measures with basis X, basis Y, or basis Z and obtains 0, then Alice must obtain 1 when measuring with basis Z; similarly, if Bob measures with basis Z and obtains 1, then Alice must obtain 0 when measuring with basis Z.

[0102] If the bit error rate of this transmission is lower than the bit error threshold, it means that the channel is safe in this transmission, and the next step can be carried out; otherwise, all photons are discarded and the process starts again. Since different channels have different bit error thresholds, they can be set according to the required level of channel security, and are not limited here.

[0103] After confirming the channel security, Alice uses sequence A photons to encode information. Alice performs quantum unitary gate operation on photon sequence A to encode information bits 0 or 1. This is the first encoding. Alice then uses another unitary gate to encode the photons after the first encoding to encode the phase information to be estimated. This is the second encoding.

[0104] In some embodiments, the phase information encoded by each photon in one transmission is the same. In other embodiments, the photons in one transmission are grouped according to the number of sensing parameters that need to be transmitted, each group transmits different sensing parameters, and the correspondence between the grouping information and the sensing parameters is sent to the receiving end Bob, so that Bob can estimate the sensing parameters of different groups respectively according to the correspondence.

[0105] In some embodiments, in order to prevent information data from being eavesdropped during transmission, Alice also randomly selects some photons in photon sequence A for disordered encoding, that is, randomly performs a set of unitary operations, the information contained in which is meaningless and is only used to prevent information from being eavesdropped.

[0106] Alice sends the processed sequence A to Bob. After Bob receives the particles, Alice informs Bob of the position information of the disordered photons and the type of the corresponding unitary operation. Bob performs Bell state measurement on the disordered photons and calculates the bit error rate. If the bit error rate is lower than the bit error threshold, it means that the transmission is safe and the next step can be taken; otherwise, all photons are discarded and the process starts again.

[0107] After both parties confirm safety, Bob uses the preset measurement operator to measure the secondary encoded photons. The information bit 0 or 1 is determined based on whether the detectors corresponding to different measurement operators respond, and the phase information is estimated based on the ratio of the responses of different detectors. Finally, the information bit is obtained and the phase parameter of the transmission is sensed at the same time.

[0108] Figure 6 A flow chart of an information transmission method based on quantum communication according to an exemplary embodiment of the present application is shown. Figure 6 The quantum communication shown includes an information transmitter Alice and an information receiver Bob, wherein Alice is used to prepare, distribute, and encode entangled photons, and Bob is used to receive, decode, and phase-aware entangled photons.

[0109] In step S601, the transmitter Alice prepares a series of entangled photon pairs A and B.

[0110] Among them, the entangled photon pair is denoted as (A 1 B 1 ,A 2 B 2,…,A i B i ,…,A m B m ), in the initial quantum state As shown in formula (10).

[0111]

[0112] Among them, i represents the i-th pair of photons in the sequence, |0> and |1> represent the photons in the horizontal and vertical polarization states, respectively, and the subscripts A and B represent the photons in sequence A and sequence B, respectively. Photon A and photon B constitute photon sequence A and photon sequence B, respectively. Alice retains photon sequence A and sends photon sequence B to Bob to complete the initial distribution of entangled pairs.

[0113] In step S603, after Bob receives the photon sequence B, Alice and Bob perform eavesdropping detection.

[0114] For example, Bob first randomly selects some photons from sequence B and randomly performs Pauli σ x , σ y or z Then Bob notifies Alice of the photon position he selected, the basis vector he used, and the measurement result. After that, Alice also performs the same basis vector measurement on the photon at the corresponding position in sequence A. Alice compares the measurement result with Bob's measurement result. The two measurement results should be opposite, otherwise it will be recorded as a bit error.

[0115] If the bit error rate of this transmission is lower than the bit error threshold, it means that the channel is safe in this transmission and the next step can be carried out; otherwise, all photons are discarded and the process starts again.

[0116] In step S605, the remaining photons in the photon sequence A are used to carry the information to be transmitted and the parameters to be transmitted.

[0117] First, the first encoding is performed to map the information bits to the quantum state of the photon.

[0118] Specifically, Alice first encodes the plaintext using two unitary operations U 0 and U 1 , as shown in formulas (1) and (2), the information bits 0 and 1 are mapped to the quantum states of photons, and the initial |ψ - >state is mapped to the quantum state shown in equations (11) and (12).

[0119]

[0120]

[0121] Then, a second encoding is performed to map the parameters to be transmitted to the quantum state of the photon after the first encoding.

[0122] Specifically, Alice parameterizes the encoded quantum state using N identical unitary operations as shown in formula (3). That is, in order to improve the accuracy, the operation shown in formula (3) is performed N times on the photon after the first encoding, and the parameters to be transmitted are encoded into the quantum state shown in formulas (11) and (12), thereby converting the quantum state into the quantum state shown in formulas (13) and (14).

[0123]

[0124]

[0125] According to an embodiment of the present application, during the encoding process, Alice will also insert disordered codes to prevent a second eavesdropping.

[0126] For example, Alice randomly selects some photons from the sequence A obtained in step S601 as sample photons according to a certain preset probability, and performs four unitary operations in an unordered manner, for example, the identity matrix I, the Pauli x-matrix σ x , the Pauli z-matrix σ z and the imaginary number multiplied by the Pauli y matrix iσ y , converting the initial quantum state into four Bell states, as shown in formulas (15) to (18).

[0127] Where I is the identity matrix, σ x ,σ z ,σ y is the Pauli x, y, z matrix.

[0128]

[0129]

[0130]

[0131]

[0132] Since disordered coded photons carry no valuable information but disordered random numbers, Alice keeps the location of the sample particles secret until she confirms that Bob has received sequence A.

[0133] In step S607, Alice sends the photon sequence A to Bob through the quantum channel.

[0134] In a specific embodiment, after receiving the photon sequence A, Bob is informed by Alice of the position of the sample photons and the unitary operator they act on. To ensure communication security, Bob performs Bell state measurements on these photons and estimates the corresponding bit error rate. If the bit error rate obtained is low enough, Alice and Bob can trust this transmission and decode the plaintext and sense the parameters; otherwise, they discard all photons and start over.

[0135] During the second transmission, any third party cannot steal valid information even if they attack to interfere with the quantum bits. This is because no one can read information from a single particle of the entangled photon pair in step S601, which means that the eavesdropper only has the maximum mixed state, and any disturbance introduced by any third party can be reflected by the bit error rate of the second transmission.

[0136] In step S609, Bob performs quantum measurement on the received photon sequence using two measurement operators, and determines the transmitted information bits based on whether the detectors corresponding to different measurement operators respond.

[0137] Specifically, the selected measurement operator is as shown in formula (4) and (5). In step S609, a measurement operator in formula (4) and (5) is randomly selected to measure the photons in the photon sequence. Then, according to formula (1) and (2) and formula (6) and (7), referring to the corresponding relationship between the preset first quantum state and the information bit, when |t 1 > and |t 2 > or |r 1 > and |r 2 >When the corresponding detector responds, the corresponding information bit is 1. When |t 3 > and |t 4 > or |r 3 > and |r 4 >When the corresponding detector responds, the corresponding information bit is 0.

[0138] In step S611, the transmitted sensing parameters are estimated according to the distribution of the transmitted information bits.

[0139] Specifically, when responding to the transmitted information bit, the number of responses of the corresponding detector is recorded. And according to the number of responses of each detector and the total number of responses of all detectors, the response ratio of each detector is calculated; then, using formula (8) and Figure 3 The response ratio of each detector is calculated using the measurement operator shown and Finally, the value of the transmitted sensing parameter is calculated according to formula (9).

[0140] In some embodiments, where Tr is the trace of a matrix, and ρ is the density matrix of the mixed state when the two quantum states in Formulas (13) and (14) each account for half.

[0141] Theoretically, the estimated values of the sensing parameters calculated using the two measurement operators through Formula (9) should be the same. However, in practical applications, there will be certain fluctuations. To address the fluctuation problem of the parameter estimated values obtained by different measurement operators, Bob obtains the estimated values of two θ using the expected values of the two measurement operators respectively, and then takes the average, as shown in Formula (19).

[0142] θ est = θ 1 + θ 2 (20)

[0143] Assume that the number of photons encoding information is ν (ν < m). Then Bob makes ν measurements. The estimated variance of the sensing parameter can be obtained according to the error propagation formula, as shown in Formula (20).

[0144]

[0145] where is the variance. Substitute and into it, and the result shown in Formula (21) is obtained.

[0146]

[0147] According to the error propagation theory shown in Formula (22), the accuracy of the estimated value of the sensing parameter obtained according to the exemplary embodiments of the present application can reach the Heisenberg limit

[0148] Next, the security of the present application is proven from two aspects: the information bit part and the parameter perception.

[0149] First, Wyner's wiretap channel theory is used to illustrate the security of the information bit part. The degree of wiretapping can be evaluated by the bit error rate.

[0150] According to the wiretap channel theory, when the secure capacity of secure transmission is positive, there exists a coding method that can securely and reliably transmit information at a rate lower than the secure capacity. The secure capacity of the present application is as shown in Formula (23).

[0151] C s = C m - C w (23)

[0152] where, Cm and C w Represent the channel capacity of the main channel and the eavesdropping channel respectively.

[0153] Without loss of generality, the eavesdropper attack is defined as a collective attack, that is, the eavesdropper performs the same and unique unitary operation on the photons in the channel to obtain the upper limit of the information that the eavesdropper can steal, as shown in formula (24).

[0154] C w =h(e) (24)

[0155] Where h(x) = -xlog 2 x-(1-x)log 2 (1-x) is Shannon entropy, and e is the bit error rate.

[0156] Assuming that the main channel is a depolarized channel, the main channel capacity is shown in formula (25).

[0157] C m =1-h[2e(1-e)] (25)

[0158] Among them, the depolarization channel is a quantum channel that describes the decoherence phenomenon of a quantum system in its interaction with the environment. The form of the depolarization channel is shown in formula (26).

[0159]

[0160] Here, p is the probability of depolarization occurring.

[0161] The safety capacity of this application is shown in formula (27).

[0162] C s =1-h[2e(1-e)]-h(e) (27)

[0163] Where e is the bit error rate of the first transmission or the second transmission.

[0164] Assuming that the two transmissions are over the same channel, the bit error rates of the two transmissions should be the same. Figure 7 It can be seen from the safety capacity curve diagram of the present application that, in order to ensure the safety of information bits, the bit error rate threshold is 7.9%.

[0165] Then, the security of the parameter-aware part is measured using the asymmetric Fisher information gain between Bob and Eve.

[0166] Substitute Bob’s two quantum states as shown in formula (13) and formula (14) into the depolarization channel and measure them using the measurement operator shown in formula (4) and (5) to obtain the new probability distribution, so as to obtain Bob’s Fisher information about the transmitted sensing parameter θ, as shown in formula (28) and (29).

[0167]

[0168]

[0169] Therefore, the Fisher information obtained by Bob satisfies the gain shown in formula (30).

[0170]

[0171] Similarly, the Fisher information gain obtained by the eavesdropper Eve is shown in formula (31).

[0172]

[0173] According to formulas (30) and (31), we can get Figure 8 The Fisher information reference curve is shown in . Figure 8 As shown, to ensure the security of parameter perception, the bit error rate threshold is 8.3%. Based on the above, it can be seen that the bit error threshold of this application is 7.9%.

[0174] According to the embodiments of the present application, quantum sensing and quantum direct communication are achieved simultaneously by transmitting entangled photons, rather than establishing separate sensing and communication systems. The accuracy of perception exceeds the standard quantum limit and can ideally approach the Heisenberg limit. At the same time, the confidentiality of information is maintained under the attack of eavesdroppers, thereby achieving quantum secure communication.

[0175] Fig. 9 An electronic device according to an exemplary embodiment of the present application is shown. Fig. 9 The electronic device 200 according to this embodiment of the present application is described. Fig. 9 The electronic device 200 shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0176] like Fig. 9 As shown, the electronic device 200 is in the form of a general computing device. The components of the electronic device 200 may include, but are not limited to: at least one processing unit 210, at least one storage unit 220, a bus 230 connecting different system components (including the storage unit 220 and the processing unit 210), a display unit 240, etc.

[0177] The storage unit stores program codes, which can be executed by the processing unit 210, so that the processing unit 210 executes the methods described in this specification according to various exemplary embodiments of the present application. For example, the processing unit 210 can execute the following: Figure 1 The method shown in .

[0178] The storage unit 220 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 2201 and / or a cache memory unit 2202 , and may further include a read-only memory unit (ROM) 2203 .

[0179] The storage unit 220 may also include a program / utility 2204 having a set (at least one) of program modules 2205, such program modules 2205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0180] Bus 230 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0181] The electronic device 200 may also communicate with one or more external devices 300 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 200, and / or communicate with any device that enables the electronic device 200 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 250. Furthermore, the electronic device 200 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 260. The network adapter 260 may communicate with other modules of the electronic device 200 via the bus 230. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 200, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0182] Through the description of the above implementation methods, it is easy for those skilled in the art to understand that the example implementation methods described here can be implemented by software or by combining software with necessary hardware. The technical solution according to the implementation method of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to execute the above method according to the implementation method of the present application.

[0183] The software product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0184] Computer readable storage media may include data signals propagated in baseband or as part of a carrier wave, wherein readable program codes are carried. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, device, or device. The program codes contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0185] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0186] The computer-readable medium carries one or more programs. When the one or more programs are executed by a device, the computer-readable medium implements the aforementioned functions.

[0187] Those skilled in the art will appreciate that the above modules can be distributed in the device according to the description of the embodiment, or can be changed accordingly and only used in one or more devices different from the embodiment. The modules of the above embodiments can be combined into one module, or further divided into multiple sub-modules.

[0188] According to an embodiment of the present application, a computer program is provided, including a computer program or an instruction. When the computer program or the instruction is executed by a processor, the method described above can be executed.

[0189] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. A method for information transmission based on quantum communication, characterized in that: include: In response to the quantum communication sensing instruction, generating a first photon sequence; Using the first photon sequence to perform a first encoding on the information bits to be transmitted, to generate a photon sequence having a first quantum state; Performing a second encoding on the sensing parameter to be transmitted to generate a photon sequence having a second quantum state; Sending a photon sequence having the second quantum state to a receiver through a quantum direct communication system; The first photon sequence is used to perform a first encoding on the information bits to be transmitted to generate a photon sequence having a first quantum state, including: Using the first photon sequence to perform a first unitary operation on the information bits to be transmitted, to generate a photon sequence having the first quantum state; The sensing parameters include phase information, and the sensing parameters to be transmitted are second-encoded to generate a photon sequence with a second quantum state, including: Performing a second unitary operation on the sensing parameter to be transmitted to generate a photon sequence having a second quantum state; The first unitary operation is shown as follows: , , where I is the identity matrix, is the Pauli x matrix, Indicates mapping the information bit 0 to the first quantum state, Indicates mapping the information bit 1 to the first quantum state, and represent the photon in horizontal and vertical polarization states, respectively. yes The conjugate transpose of yes The conjugate transpose of ; The second unitary operation is shown as follows: ， in, is the second unitary operation, and represent the photon in horizontal and vertical polarization states, respectively. is the sensing parameter.

2. The information transmission method according to claim 1, characterized in that: Before sending the photon sequence having the second quantum state to a receiver through a quantum direct communication system, the method further includes: Generating an entangled photon sequence having the same quantum state as the first photon sequence to obtain a second photon sequence; The second photon sequence is used to detect the channel security of the quantum direct communication system.

3. The information transmission method according to claim 1, characterized in that: Using the first photon sequence to perform a first encoding on the information bits to be transmitted to generate a photon sequence having a first quantum state, comprising: According to the preset corresponding relationship between the first quantum state and the information bit, the first photon sequence is used to perform a first encoding on the information bit to be transmitted to generate a photon with a first quantum state.

4. The information transmission method according to claim 1, characterized in that: Also includes: The first photon sequence is randomly encoded to be used for eavesdropping detection of the quantum direct communication system.

5. A method for information transmission based on quantum communication, characterized in that: include: receiving a photon sequence having a second quantum state sent from a sender; Decoding the photon sequence having the second quantum state to obtain transmission information; estimating the transmitted sensing parameters according to the quantity distribution of the transmitted information; Wherein, the second quantum state is obtained by the sender in the following manner: Using the first photon sequence to perform a first unitary operation on the information bits to be transmitted, generating a photon sequence having a first quantum state; and Performing a second unitary operation on the sensing parameter to be transmitted to generate a photon sequence having a second quantum state; The first unitary operation is shown as follows: , , where I is the identity matrix, is the Pauli x matrix, Indicates mapping the information bit 0 to the first quantum state, Indicates mapping the information bit 1 to the first quantum state, and represent the photon in horizontal and vertical polarization states, respectively. yes The conjugate transpose of yes The conjugate transpose of ; The second unitary operation is shown as follows: ， in, is the second unitary operation, and represent the photon in horizontal and vertical polarization states, respectively. is the sensing parameter.

6. The information transmission method according to claim 5, characterized in that: Decoding the second quantum state to obtain transmission information includes: The second quantum state is decoded using a preset measurement operator to obtain transmission information.

7. The information transmission method according to claim 6, characterized in that: The sensing parameters include phase information, and the transmitted sensing parameters are estimated according to the quantity distribution of the transmitted information, including: Calculating an expected value of the measurement operator based on the quantity distribution of the detector responses corresponding to the measurement operator; The phase information is estimated according to the expected value.

8. The information transmission method according to claim 6, characterized in that: The measurement operator is shown below: ， 。 9. An electronic device, characterized in that: include: A memory and a processor; wherein the memory stores one or more computer instructions, wherein when the one or more computer instructions are executed by the processor, the information transmission method as described in any one of claims 1-8 is implemented.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the information transmission method according to any one of claims 1 to 8 is implemented.

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