A three-party quantum secure direct communication method with identity authentication function

Abstract

The application discloses a three-party quantum secure direct communication method with identity authentication function, which realizes three-party quantum secure direct communication with identity authentication function by using polarization-space hyper-encoding single photons; first, Alice prepares polarization-space hyper-encoding single photons and sends the single photons to Bob'1, and the identity of Bob'1 is determined through identity authentication; after the identity of Bob'1 is determined, Bob'1 encodes the single photons in the polarization degree of freedom; then the photon sequence is sent to Bob'2, and the identity of Bob'2 is determined through identity authentication; after the identity of Bob'2 is determined, Bob'2 encodes the single photons in the space degree of freedom; after the encoding is completed, the encoded single photons are re-sent to the information receiver; Alice can obtain the secret information transmitted by the two information senders at the same time through measurement; compared with the previous three-party quantum secure direct communication scheme, the present scheme determines the identities of the two information senders before realizing information transmission, and can effectively improve the security of communication in the actual experimental environment, and has important application in the field of quantum communication.

Description

Technical Field

[0001] This invention relates to a three-party quantum-secure direct communication method with identity authentication function, belonging to the field of quantum communication technology. Background Technology

[0002] Quantum secure communication aims to protect information security using the fundamental principles of quantum mechanics. Quantum Secure Direct Communication (QSDC) is an important branch of quantum secure communication. The main purpose of the QSDC protocol is to use quantum channels to directly transmit information between receivers without requiring both parties to share a key beforehand. QSDC can also be used to transmit keys.

[0003] In practical quantum secure communication and quantum networks, authentication is a crucial and indispensable component. Before communication, the communicating parties need to authenticate each other to ensure their legitimacy. Classical authentication methods rely on mathematical computational difficulty. Unlike classical authentication, quantum authentication is based on the fundamental principles of quantum mechanics and theoretically possesses absolute security.

[0004] In the field of Multi-Party Quantum Secure Direct Communication (MQSDC), an important research branch of QSDC, MQSDC allows multiple information receivers to simultaneously and independently transmit information to each other. However, existing MQSDC protocols can only transmit information and lack authentication functionality. In practical applications, eavesdroppers could impersonate the communicating parties and steal information. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a three-party quantum secure direct communication method with identity authentication function, thereby solving the technical problem that the MQSDC protocol cannot authenticate identities when transmitting information.

[0006] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0007] This invention provides a three-party quantum-secure direct communication method with identity authentication function, comprising:

[0008] The receiver, Alice, prepares a photon sequence S″1 and sends it to the actual communicator, Bob′1, and publishes the position and quantum state of the security detection photon in the photon sequence S″1;

[0009] In response to the position and quantum state of the photons in the photon sequence S″1 sent by the receiver Alice and the published photon sequence S″1, the actual communicator Bob′1 performs the first round of security checks and publishes them;

[0010] In response to the information released by the actual communicator Bob′1 regarding the successful completion of the first round of security checks, the receiver Alice released the location of the authentication photon of the target sender Bob1 in the photon sequence S″1.

[0011] In response to the position of the authentication photon of the target sender Bob1 in the photon sequence S″1 published by the receiver Alice, the actual communicator Bob′1 performs the authentication photon measurement and publishes it.

[0012] In response to the identity verification photon measurement results published by the actual communicator Bob′1, the receiver Alice verifies the identity of the actual communicator Bob′1. If the identity verification is successful, the actual communicator Bob′1 is identified as the target sender Bob1 and published, and the position of the identity verification photon of the target sender Bob2 in the photon sequence S″1 is also published.

[0013] In response to the identity verification information of the actual communicator Bob′1 published by the receiver Alice and the position of the target sender Bob2 in the photon sequence S″1, the actual communicator Bob′1 updates the photon sequence S″1 to generate the photon sequence S′2 and sends it to the actual communicator Bob′2, and publishes the position and quantum state of the security detection photon in the photon sequence S′2.

[0014] In response to the position and quantum state of the security detection photon in the photon sequence S′2 sent by the actual communicator Bob′1 and the published photon sequence S′2, the actual communicator Bob′2 ​​conducts a second round of security detection. If the second round of security detection passes, the identity authentication photon measurement is performed and published.

[0015] In response to the photon measurement results of the identity verification published by the actual communicator Bob′2, the receiver Alice verifies the identity of the actual communicator Bob′2. If the identity verification is successful, the actual communicator Bob′2 ​​is identified as the target sender Bob2 and the result is published.

[0016] In response to the authentication information of the actual communicator Bob′2 ​​published by the receiver Alice, the actual communicator Bob′2 ​​updates the photon sequence S′2 to generate the photon sequence S′3 and sends it to the receiver Alice, and publishes the position and quantum state of the security detection photon in the photon sequence S′3;

[0017] In response to the photon sequence S′3 sent by the actual communicator Bob′2 ​​and the position and quantum state of the security detection photon in the published photon sequence S′3, the receiver Alice performs a third round of security detection. If the third round of security detection passes, the information transmission photon in the photon sequence S′3 is decoded to obtain the transmission information.

[0018] Preferably, the preparation process of the photon sequence S″1 includes:

[0019] Multiple single photons supercoded in polarization-space degrees of freedom are randomly prepared as information transmission photons, and a photon sequence S1 is generated based on the information transmission photons;

[0020] Based on the identity codes of the target senders Bob1 and Bob2, prepare a corresponding number of single photons encoded in polarization degrees of freedom as identity authentication photons, and randomly insert the identity authentication photons into the photon sequence S1 to generate the photon sequence S′1;

[0021] Multiple single photons supercoded in polarization-space degrees of freedom are randomly prepared as security detection photons, and the security detection photons are randomly inserted into the photon sequence S′1 to generate the photon sequence S″1;

[0022] The identity codes of the target senders Bob1 and Bob2 are a set of random key sequences K1 and K2 shared by the receiver Alice with the target senders Bob1 and Bob2, respectively.

[0023] Preferably, the key sequences K1 and K2 are shared via the BB84 protocol, and the key sequences K1 and K2 are respectively:

[0024] K1={k 11 ,k 12 ,k 13 ,…k 1i …,k 1n}

[0025] K2={k 21 ,k 22 ,k 23 ,…k 2i …,k 2n}

[0026] In the formula, k 1i k 2i Let be the i-th key bit in key sequences K1 and K2, respectively, and n be the number of key bits.

[0027] Preferably, the preparation of multiple single photons super-coded in polarization-space degrees of freedom includes:

[0028] For the polarization degree of freedom of a single photon, prepare the corresponding quantum state:

[0029]

[0030] In the formula, |H> and |V> represent the horizontal and vertical polarization states of the photon, respectively.

[0031] For the spatial degree of freedom of a single photon, prepare the corresponding quantum state:

[0032]

[0033] In the formula, |a1> and |a2> represent the propagation of photons along paths a1 and a2, respectively.

[0034] Based on the quantum states of a single photon in the polarization and spatial degrees of freedom, a quantum state over-encoded in the polarization-spatial degrees of freedom is formed:

[0035]

[0036]

[0037]

[0038]

[0039] Preferably, the step of preparing a corresponding number of single photons encoded in polarization degrees of freedom based on the identity codes of the target senders Bob1 and Bob2 includes:

[0040] Based on each key in the identity code, prepare its corresponding single photon in sequence:

[0041] When the i-th key bit k in the identity code of the target sender Bob1 or Bob2 1i k 2i When the value is 0, single photons with quantum states |H> and |V> are prepared using a right-angled basis;

[0042] When the i-th key bit k in the identity code of the target sender Bob1 or Bob2 1i k 2i When the value is 1, single photons with quantum states |+> and |-> are prepared using a diagonal basis; among them,

[0043] Preferably, the first round of security checks performed by the actual communicating party Bob′1 includes:

[0044] Based on the position of the security detection photon in the published photon sequence S″1, extract the security detection photon from the photon sequence S″1;

[0045] Based on the quantum states of the security detection photons in the published photon sequence S″1, measurement bases are selected for each security detection photon in terms of polarization and spatial degrees of freedom:

[0046] If the quantum state of the security detection photon in the polarization degree of freedom is {|H>,|V>}, then the chosen measurement basis is a rectangular basis. The chosen measurement basis is the diagonal basis;

[0047] If the quantum state of the security detection photon in spatial degrees of freedom is {|a1>,|a2>}, then the chosen measurement basis is a rectangular basis. The chosen measurement basis is the diagonal basis;

[0048] Based on the selected measurement basis, the polarization degree of freedom and spatial degree of freedom of each security detection photon are measured separately, and the measurement results are matched with the quantum state of the security detection photon in the published photon sequence S″1.

[0049] Based on the consistency matching results, the security detection error rate is calculated for both polarization degree of freedom and spatial degree of freedom. If the security detection error rate for both polarization degree of freedom and spatial degree of freedom is lower than the corresponding error rate threshold, then the first round of security detection passes.

[0050] Preferably, the identity authentication photon measurement performed by the actual communicating party Bob′1 includes:

[0051] Based on the position of the identity authentication photon of the target sender Bob1 in the published photon sequence S″1, extract the identity authentication photon of the target sender Bob1 from the photon sequence S″1.

[0052] Based on the identity code of Bob′1, the actual communicator, a measurement basis is selected for each authenticated photon:

[0053] When the i-th key bit k in the identity code of the actual communicator Bob′1 1i When the value is 0, the selected measurement basis is a right-angled basis;

[0054] When the i-th key bit k in the identity code of the actual communicator Bob′1 1i When the value is 1, the selected measurement basis is the diagonal basis;

[0055] The polarization degrees of freedom of each authentication photon are measured according to the selected measurement basis;

[0056] The authentication process performed by the receiver Alice on the actual communicator Bob′1 includes:

[0057] The consistency matching of the identity authentication photon measurement results published by the actual communicator Bob′1 with the quantum state of the identity authentication photon of the target sender Bob1 in the photon sequence S″1 is performed.

[0058] The identity authentication error rate is calculated based on the consistency matching results. If the identity authentication error rate is lower than the corresponding error rate threshold, the identity authentication is successful.

[0059] Preferably, the process by which the actual communicating party Bob′1 updates the photon sequence S″1 to generate the photon sequence S′2 includes:

[0060] Based on the positions of the authentication photons and security detection photons of the target senders Bob1 and Bob2 in the published photon sequence S″1, the positions of the information transmission photons in the photon sequence S″1 are determined.

[0061] The information transmission photons in photon sequence S″1 are determined based on their positions.

[0062] Encode each information-transmitting photon in its polarization degree of freedom:

[0063] When the amount of confidential information that Bob′1, the actual communicator, needs to transmit is 0, select... Perform unitary operations on quantum states:

[0064]

[0065]

[0066]

[0067]

[0068] in,

[0069] When Bob′1, the actual communicator, needs to transmit 1 unit of confidential information, select... Perform unitary operations on quantum states:

[0070]

[0071]

[0072]

[0073]

[0074] The photon sequence after extracting the security detection photon and the identity authentication photon of the target sender Bob1 from the photon sequence S″1, and encoding the information transmission photon, is denoted as photon sequence S2;

[0075] Multiple single photons supercoded in polarization-space degrees of freedom are randomly prepared as security detection photons, and the security detection photons are randomly inserted into the photon sequence S2 to generate the photon sequence S′2.

[0076] Preferably, the process by which the actual communicating party Bob′2 ​​updates the photon sequence S′2 to generate the photon sequence S′3 includes:

[0077] Based on the position of the identity authentication photon of the target sender Bob2 in the published photon sequence S″1 and the position of the security detection photon in the published photon sequence S′2, the position of the information transmission photon in photon sequence S′2 is determined.

[0078] The information-transmitting photons in photon sequence S′2 are determined based on their positions.

[0079] Encode each information-transmitting photon in its spatial degrees of freedom:

[0080] When the amount of confidential information that Bob′2, the actual communicator, needs to transmit is 0, select... Perform unitary operations on quantum states:

[0081]

[0082]

[0083]

[0084]

[0085] in,

[0086] When Bob′2, the actual communicator, needs to transmit 1 unit of confidential information, select... Perform unitary operations on quantum states:

[0087]

[0088]

[0089]

[0090]

[0091] The photon sequence after extracting the security detection photon and the identity authentication photon of the target sender Bob2 from the photon sequence S′2, and encoding the information transmission photon, is denoted as photon sequence S3;

[0092] Multiple single photons supercoded in polarization-space degrees of freedom are randomly prepared as security detection photons, and the security detection photons are randomly inserted into the photon sequence S3 to generate the photon sequence S′3.

[0093] Preferably, the receiving party Alice decodes and obtains the transmitted information by:

[0094] Based on the position of the security detection photon in the published photon sequence S′3, determine the position of the information transmission photon in the photon sequence S′3;

[0095] Based on the position of the information transmission photon in photon sequence S′3, extract the information transmission photon from photon sequence S′3;

[0096] Based on the initial quantum state of the information transmission photons in the photon sequence S′3, the corresponding measurement basis is selected for each information transmission photon extracted from the photon sequence S′3 in terms of polarization degree of freedom and spatial degree of freedom;

[0097] Based on the selected measurement basis, the information transmission photons extracted from the photon sequence S′3 are measured in polarization degree of freedom and spatial degree of freedom, respectively.

[0098] Based on the measurement results and the quantum states of each information transmission photon in the photon sequence S″1, the encoding information of the actual communicators Bob′1 and Bob′2 ​​is determined, and the encoding information is used as the transmission information of the target senders Bob1 and Bob2.

[0099] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0100] This invention provides a three-party quantum secure direct communication method with identity authentication function, which improves the multi-party quantum secure direct communication protocol. By encoding the two degrees of freedom (polarization degree of freedom and spatial degree of freedom) of a single photon respectively, it can not only increase the information capacity of a single photon during information transmission, thereby improving the information transmission efficiency of the scheme, but also realize the identity authentication of the two users, enhancing the security of multi-party quantum secure direct communication under actual experimental conditions. Attached Figure Description

[0101] Figure 1 This is a flowchart of a three-party quantum-secure direct communication method with identity authentication function provided in an embodiment of the present invention;

[0102] Figure 2 This is a schematic diagram illustrating the photon sequence changes during the implementation of the three-party quantum-secure direct communication method provided in this embodiment of the invention. Detailed Implementation

[0103] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0104] Example 1:

[0105] like Figure 1 As shown, this invention provides a three-party quantum-secure direct communication method with identity authentication function, including the following steps:

[0106] 1. The receiver Alice prepares a photon sequence S″1 and sends it to the actual communicator Bob′1, and publishes the position and quantum state of the security detection photon in the photon sequence S″1;

[0107] 2. In response to the position and quantum state of the photons in the photon sequence S″1 sent by the receiver Alice and the published photon sequence S″1, the actual communicator Bob′1 performs the first round of security detection and publishes the information.

[0108] In this embodiment, before communication, the receiver Alice shares a set of random key sequences K1 and K2 with the target senders Bob1 and Bob2 respectively, and uses key sequences K1 and K2 as the identity codes of the target senders Bob1 and Bob2 respectively; key sequences K1 and K2 are shared via the BB84 protocol, and key sequences K1 and K2 are respectively represented as:

[0109] K1={k 11 ,k 12 ,k 13 ,…k 1i …,k 1n}

[0110] K2={k 21 ,k 22 ,k 23 ,…k 2i …,k 2n}

[0111] In the formula, k 1i k 2i Let be the i-th key bit in key sequences K1 and K2, respectively, and n be the number of key bits.

[0112] The preparation process of the photon sequence S″1 sent by the receiver Alice includes:

[0113] (1) Randomly prepare multiple single photons supercoded in polarization-space degrees of freedom as information transmission photons, and generate photon sequence S1 based on the information transmission photons;

[0114] Specifically, the preparation of multiple single photons super-encoded in polarization-space degrees of freedom includes:

[0115] For the polarization degree of freedom of a single photon, prepare the corresponding quantum state:

[0116]

[0117] In the formula, |H> and |V> represent the horizontal and vertical polarization states of the photon, respectively.

[0118] For the spatial degree of freedom of a single photon, prepare the corresponding quantum state:

[0119]

[0120] In the formula, |a1> and |a2> represent the propagation of photons along paths a1 and a2, respectively.

[0121] Based on the quantum states of a single photon in the polarization and spatial degrees of freedom, a quantum state over-encoded in the polarization-spatial degrees of freedom is formed:

[0122]

[0123]

[0124]

[0125]

[0126] The advantage of using supercoded single photons is that it can increase the channel capacity of single photons, and its multiple degrees of freedom are independent of each other and do not affect each other. Alice can read the encoded information of the two communicating parties in two degrees of freedom respectively.

[0127] (2) The receiver Alice prepares a corresponding number of single photons encoded in polarization degrees of freedom as identity authentication photons based on the identity codes of the target senders Bob1 and Bob2, and randomly inserts the identity authentication photons into the photon sequence S1 to generate the photon sequence S′1.

[0128] Specifically, preparing a corresponding number of single photons encoded in polarization degrees of freedom based on the identity codes of the target senders Bob1 and Bob2 includes:

[0129] Based on each key in the identity code, prepare its corresponding single photon in sequence:

[0130] When the i-th key bit k in the identity code of the target sender Bob1 or Bob2 1i k 2i When the value is 0, single photons with quantum states |H> and |V> are prepared using a right-angled basis;

[0131] When the i-th key bit k in the identity code of the target sender Bob1 or Bob2 1i k 2i When the value is 1, single photons with quantum states |+> and |-> are prepared using a diagonal basis; among them,

[0132] (3) Randomly prepare multiple single photons supercoded in polarization-space degrees of freedom as security detection photons, and randomly insert the security detection photons into the photon sequence S′1 to generate the photon sequence S″1; the preparation method of the security detection photons here is the same as the preparation method of the information transmission photons mentioned above.

[0133] The first round of security checks conducted by Bob′1, the actual communicator, included:

[0134] S1. Based on the position of the security detection photon in the published photon sequence S″1, extract the security detection photon from the photon sequence S″1.

[0135] S2. Based on the quantum states of the security detection photons in the published photon sequence S″1, select measurement bases for each security detection photon in terms of polarization and spatial degrees of freedom:

[0136] If the quantum state of the security detection photon in the polarization degree of freedom is {|H>,|V>}, then the chosen measurement basis is a rectangular basis. The chosen measurement basis is the diagonal basis;

[0137] If the quantum state of the security detection photon in spatial degrees of freedom is {|a1>,|a2>}, then the chosen measurement basis is a rectangular basis. The chosen measurement basis is the diagonal basis;

[0138] S3. Measure each security detection photon in polarization and spatial degrees of freedom according to the selected measurement basis, and perform consistency matching between the measurement results and the quantum states of the security detection photons in the published photon sequence S″1.

[0139] S4. Calculate the security detection error rate (i.e., the number of failed consistency matchings divided by the number of consistent matchings) on the polarization degree of freedom and the spatial degree of freedom respectively based on the consistency matching results. If the security detection error rate on both the polarization degree of freedom and the spatial degree of freedom is lower than the corresponding error rate threshold, then the first round of security detection passes.

[0140] 3. In response to the first round of security test pass information announced by the actual communicator Bob′1, the receiver Alice announces the location of the identity authentication photon of the target sender Bob1 in the photon sequence S″1.

[0141] 4. In response to the position of the authentication photon of the target sender Bob1 in the photon sequence S″1 published by the receiver Alice, the actual communicator Bob′1 measures and publishes the authentication photon.

[0142] Among them, the photon measurement for identity authentication performed by the actual communicating party Bob′1 includes:

[0143] (1) Based on the position of the identity authentication photon of the target sender Bob1 in the published photon sequence S″1, extract the identity authentication photon of the target sender Bob1 from the photon sequence S″1;

[0144] (2) Based on the identity code of the actual communicator Bob′1, select a measurement basis for each authenticated photon:

[0145] When the i-th key bit k in the identity code of the actual communicator Bob′1 1i When the value is 0, the selected measurement basis is a right-angled basis;

[0146] When the i-th key bit k in the identity code of the actual communicator Bob′1 1i When the value is 1, the selected measurement basis is the diagonal basis;

[0147] (3) Measure the polarization degrees of freedom of each identity authentication photon according to the selected measurement basis.

[0148] 5. In response to the identity verification photon measurement results published by the actual communicator Bob′1, the receiver Alice verifies the identity of the actual communicator Bob′1. If the identity verification is successful, the actual communicator Bob′1 is identified as the target sender Bob1 and published, and the position of the identity verification photon of the target sender Bob2 in the photon sequence S″1 is also published.

[0149] The authentication process performed by the receiver Alice on the actual communicator Bob′1 includes:

[0150] The consistency matching of the identity authentication photon measurement results published by the actual communicator Bob′1 with the quantum state of the identity authentication photon of the target sender Bob1 in the photon sequence S″1 is performed.

[0151] The identity authentication error rate is calculated based on the consistency matching results (i.e., the number of unsuccessful consistency matchings divided by the number of consistency matchings). If the identity authentication error rate is lower than the corresponding error rate threshold, then the identity authentication is successful.

[0152] Here's an example of identity authentication:

[0153] Assume the i-th bit k of Bob1's identity code 1i=0, therefore, the photon prepared using the rectangular basis (Z basis) is used as Bob's authentication photon. If Bob's is a legitimate communicator, the authentication photon is measured using the rectangular basis (Z basis), and the measurement result is published. If the result is consistent with the initial state prepared by Alice, then Alice considers Bob's identity code correct. If Bob's is an illegitimate communicator, there is a 1 / 2 probability that the diagonal basis (X basis) measurement will be chosen, resulting in either |+> or |-> state. The result is inconsistent with the initial state prepared by Alice (|H> or |V>), then Alice considers Bob's identity code incorrect.

[0154] 6. In response to the identity authentication information of the actual communicator Bob′1 published by the receiver Alice and the position of the target sender Bob2 in the photon sequence S″1, the actual communicator Bob′1 updates the photon sequence S″1 to generate the photon sequence S′2 and sends it to the actual communicator Bob′2, and publishes the position and quantum state of the security detection photon in the photon sequence S′2.

[0155] Specifically, the actual communicating party Bob′1 updates the photon sequence S″1 to generate the photon sequence S′2, including:

[0156] (1) Determine the position of the information transmission photon in photon sequence S″1 based on the position of the identity authentication photon and the security detection photon of the target sender Bob1 and Bob2 in the published photon sequence S″1;

[0157] (2) Determine the information transmission photons in photon sequence S″1 based on their positions;

[0158] (3) Encode each information transmission photon in its polarization degree of freedom:

[0159] When the amount of confidential information that Bob′1, the actual communicator, needs to transmit is 0, select... Perform unitary operations on quantum states:

[0160]

[0161]

[0162]

[0163]

[0164] in,

[0165] When Bob′1, the actual communicator, needs to transmit 1 unit of confidential information, select... Perform unitary operations on quantum states:

[0166]

[0167]

[0168]

[0169]

[0170] (4) The photon sequence after extracting the security detection photon and the identity authentication photon of the target sender Bob1 from the photon sequence S″1 and encoding the information transmission photon is denoted as photon sequence S2.

[0171] (5) Randomly prepare multiple single photons supercoded in polarization-space degrees of freedom as security detection photons, and randomly insert the security detection photons into the photon sequence S2 to generate the photon sequence S′2.

[0172] 7. In response to the position and quantum state of the security detection photon in the photon sequence S′2 sent by the actual communicator Bob′1 and the published photon sequence S′2, the actual communicator Bob′2 ​​conducts a second round of security detection. If the second round of security detection passes, the identity authentication photon measurement is performed and published.

[0173] The second round of security testing uses the same method as the first round of security testing; the method for identity authentication photon measurement is also the same as above.

[0174] Among them, the authentication photons extracted by the actual communicating party Bob′2 ​​from the target sender Bob2 include:

[0175] Regarding photon sequence S′2, since the randomly inserted security detection photons were extracted during the second round of security detection, Bob′2, the actual communicating party, can extract the identity authentication photons of the target sender Bob2 from photon sequence S′2 based on the position of the target sender Bob2's authentication photons in the published photon sequence S′1. Bob′2 ​​then measures and publishes the extracted identity authentication photons.

[0176] 8. In response to the identity verification photon measurement results published by the actual communicator Bob′2, the receiver Alice verifies the identity of the actual communicator Bob′2. If the identity verification is successful, the actual communicator Bob′2 ​​is identified as the target sender Bob2 and the identity is published.

[0177] Among them, the photon measurement and authentication of the actual communicating party Bob′2 ​​are the same as those of the actual communicating party Bob′1 mentioned above.

[0178] 9. In response to the authentication information of the actual communicator Bob′2 ​​published by the receiver Alice, the actual communicator Bob′2 ​​updates the photon sequence S′2 to generate the photon sequence S′3 and sends it to the receiver Alice, and publishes the position and quantum state of the security detection photon in the photon sequence S′3;

[0179] Specifically, the actual communicating party Bob′2 ​​updates the photon sequence S′2 to generate the photon sequence S′3, including:

[0180] (1) Based on the position of the identity authentication photon of the target sender Bob2 in the published photon sequence S″1 and the position of the security detection photon in the published photon sequence S′2, determine the position of the information transmission photon in the photon sequence S′2;

[0181] (2) Determine the information transmission photons in photon sequence S′2 based on their positions;

[0182] (3) Encode each information-transmitting photon in its spatial degrees of freedom:

[0183] When the amount of confidential information that Bob′2, the actual communicator, needs to transmit is 0, select... Perform unitary operations on quantum states:

[0184]

[0185]

[0186]

[0187]

[0188] in,

[0189] When Bob′2, the actual communicator, needs to transmit 1 unit of confidential information, select... Perform unitary operations on quantum states:

[0190]

[0191]

[0192]

[0193]

[0194] (4) The photon sequence after extracting the security detection photon and the identity authentication photon of the target sender Bob2 from the photon sequence S′2 and encoding the information transmission photon is denoted as photon sequence S3;

[0195] (5) Randomly prepare multiple single photons supercoded in polarization-space degrees of freedom as security detection photons, and randomly insert the security detection photons into the photon sequence S3 to generate the photon sequence S′3.

[0196] 10. In response to the position and quantum state of the security detection photon in the photon sequence S′3 sent by the actual communicator Bob′2 ​​and the published photon sequence S′3, the receiver Alice performs a third round of security detection. If the third round of security detection passes, the information transmission photon in the photon sequence S′3 is decoded to obtain the transmission information.

[0197] The third round of security testing uses the same methods as the first and second rounds of security testing.

[0198] The receiving party, Alice, decodes and obtains the transmitted information, including:

[0199] (1) Determine the position of the information transmission photon in the photon sequence S′3 based on the position of the security detection photon in the published photon sequence S′3;

[0200] (2) Extract the information transmission photons from the photon sequence S′3 based on the positions of the information transmission photons in the photon sequence S′3;

[0201] (3) Based on the initial quantum state of the information transmission photons in the photon sequence S′3, select the corresponding measurement basis for each information transmission photon extracted from the photon sequence S′3 in terms of polarization degree of freedom and spatial degree of freedom;

[0202] The process for selecting the measurement basis is as follows: If the preparation basis for information transmission photons is a diagonal basis, then Alice's measurement basis is selected as a diagonal basis; if the preparation basis for information transmission photons is a right-angle basis, then Alice's measurement basis is selected as a right-angle basis.

[0203] (4) Based on the selected measurement basis, the information transmission photons extracted from the photon sequence S′3 are measured in polarization degree of freedom and spatial degree of freedom respectively;

[0204] (5) Based on the measurement results, compare them with the quantum states of each information transmission photon in the photon sequence S″1 to determine the encoding information of the actual communication parties Bob′1 and Bob′2, and use the encoding information as the transmission information of the target senders Bob1 and Bob2.

[0205] Here's an example illustrating how decoding and obtaining transmitted information works:

[0206] Assume that the single-photon state of the information transmission photon prepared by Alice is Bob′1 needs to transmit 1, and Bob′2 ​​needs to transmit 0.

[0207] Bob′1 selects according to the photonic coding rules for information transmission. Performing a unitary operation on the polarization degree of freedom, the single-photon state is then... Bob′2 ​​selects based on the photonic coding rules for information transmission. Performing a unitary operation on the spatial degrees of freedom, the single-photon state is then...

[0208] Based on the information obtained during preparation, Alice selected a right-angled basis (Z basis) for the polarization degree of freedom and a diagonal basis (X basis) for the spatial degree of freedom to measure the transmitted photon, obtaining the quantum state of the polarization degree of freedom as |H> and the quantum state of the spatial degree of freedom as |+>. S Therefore, Alice determines that Bob′1 performs a bit flip operation on the quantum state of the polarization degree of freedom, and decodes the information of Bob′1 as 1; Bob′2 ​​performs an invariant operation on the quantum state of the spatial degree of freedom, and decodes the information of Bob′2 ​​as 0.

[0209] like Figure 2 As shown, the specific operation process of the three-party quantum-secure direct communication method with authentication function provided in this embodiment includes:

[0210] S1: Before communication, Alice shares a set of random key sequences K1 and K2 with the target senders Bob1 and Bob2 respectively as the identity codes of Bob1 and Bob2;

[0211] S2: Alice randomly prepares a large number of polarization-spatial super-coded single photons as information transmission photons to form sequence S1. Then, based on the identity codes of Bob1 and Bob2, she prepares a corresponding number of identity authentication photons and randomly inserts them into sequence S1 to form sequence S′1. Finally, she randomly prepares a large number of security detection photons and randomly inserts them into sequence S′1 to form sequence S″1. Sequence S″1 is then sent to the first actual communicator, Bob′1.

[0212] S3: After receiving all photons, Bob'1 stores them in a quantum memory. Alice announces the position and quantum state of the security detection photon. Bob'1 retrieves the security detection photon from the quantum memory and performs the first round of security detection. If the security detection fails, communication terminates; if the security detection passes, the next step is performed.

[0213] S4: Alice announces the location of the authentication photon used for Bob'1. Bob'1 retrieves the authentication photon from the quantum memory, selects a measurement basis according to his identity code, measures it, and publishes the measurement result. Alice compares the published result with the prepared initial state to perform identity authentication. If the authentication is successful, the actual communicator Bob'1 is considered to be the target sender Bob'1, and the next step is performed. If the authentication fails, the first actual communicator Bob'1 is considered an unauthorized user, and communication is canceled.

[0214] S5: Alice announces the location of the photon used for Bob'2's identity authentication. The remaining photons are the information transmission photons. Bob'1 extracts the information transmission photons from the quantum memory, encodes them on their polarization degrees of freedom, and forms sequence S2. Bob'1 randomly inserts a sufficient number of security detection photons into sequence S2 to form sequence S2, and sends sequence S2 to the second actual communicator, Bob'2.

[0215] S6: After receiving the photon, Bob′2 ​​stores it in a quantum memory. Bob′1 publishes the position and quantum state of the security detection photon in sequence S′2. Bob′2 ​​retrieves the security detection photon from the quantum memory for a second round of security detection. If the security detection fails, communication terminates; if the security detection passes, the next step is performed.

[0216] S7: Bob′2 ​​extracts the identity authentication photon based on the location of the authentication photon published by Alice in S5 and the location of the security detection photon published by Bob1. Bob′2 ​​selects a measurement base based on his own identity code to measure it and publishes the measurement results.

[0217] Alice performs identity authentication by comparing the published results with the prepared initial state. If the authentication is successful, the actual communicator Bob′2 ​​is considered to be the target sender Bob2, and the process proceeds to the next step. If the authentication fails, the second actual communicator Bob′2 ​​is considered an unauthorized user, and the communication is canceled.

[0218] S8: Bob′2 ​​extracts information transmission photons from the quantum memory, encodes them on their spatial degrees of freedom, and forms sequence S3. Bob′2 ​​randomly inserts a sufficient number of security detection photons into sequence S3 to form sequence S′3, and sends sequence S′3 to Alice;

[0219] S9: After receiving all photons, Alice stores them in a quantum memory. Bob′2 ​​announces the position and quantum state of the security detection photon in sequence S′3. Alice extracts the security detection photon for the third round of security testing. If the security test fails, communication terminates; if the security test passes, the next step is performed.

[0220] S10: Alice measures the two degrees of freedom of each information transmission photon and compares them with the quantum state of the corresponding information transmission photon in the original sequence S1, thereby decoding the encoded information of Bob′1 and Bob′2.

[0221] To facilitate understanding, we will analyze the overall process of this invention with specific examples below, assuming:

[0222] Bob1's identification code is 10, and the transmitted information is 110;

[0223] Bob2's identification code is 11, and the transmitted information is 010.

[0224] First, Alice prepares a series of randomly encoded single photons in polarization and spatial degrees of freedom, which serve as the information transmission photons that make up sequence S1:

[0225]

[0226] Alice prepares single photons encoded in polarization degrees of freedom as authentication photons based on Bob1 and Bob2's identity codes: For Bob1's two authentication photons, they are prepared sequentially using the diagonal basis (X basis) |-> I1 State and preparation using right-angled groups (Z groups) |H> I1 Similarly, for Bob2's two authentication photons, the diagonal basis (X basis) is used sequentially to prepare |-> I2 State and preparation using diagonal basis (X basis) |+> I2 state.

[0227] The authentication photon is randomly inserted into sequence S1. Alice records the position and quantum state of the authentication photon. At this time, the photon sequence is:

[0228]

[0229] To ensure the security of the communication transmission process, Alice randomly inserts single photons with random codes on two degrees of freedom as security detection photons, and randomly inserts them into the above sequence to form sequence S′1. Alice sends S′1 to Bob′1. After Bob′1 receives all the photons, Alice announces the position of the security detection photons and the quantum states of the two degrees of freedom, and Bob′1 performs the first round of security checks.

[0230] After the security check is passed, Alice publishes the location of Bob1's authentication photon, and Bob'1 retrieves it. If Bob'1 is a legitimate user, based on the measurement of the authentication photon, Bob'1 selects a diagonal basis (X-basis) and a right-angle basis (Z-basis) to measure the photon. Bob'1 obtains the measurement result {|->,|H>} and publishes it. Alice authenticates Bob'1's identity based on the published result. If Bob'1 is an illegitimate user, Bob'1 randomly selects a measurement basis to measure the authentication photon, for example, a right-angle basis (Z-basis) and a diagonal basis (X-basis). Bob'1 obtains one of four measurement results: {|H>,|+>}, {|H>,|->}, {|V>,|+>}, or {|V>,|->}. Therefore, Alice determines that Bob'1 is an illegitimate user based on the published result.

[0231] After successful authentication, Alice reveals the location of Bob2's identity code. At this point, the sequence of single photons is:

[0232]

[0233] According to Bob′1’s information encoding rules, Bob′1 sequentially performs unitary operations on the polarization degrees of freedom of the information transmission photons. and Forming a single-photon sequence S2:

[0234]

[0235] Bob′1 randomly inserts a single photon, randomly encoded in two degrees of freedom, as a security detection photon, and randomly inserts it into S2 to form S′2. Bob′1 sends S′2 to Bob′2. After Bob′2 ​​receives all the photons, Bob′1 announces the position of the security detection photon and the quantum state of the two degrees of freedom, and Bob′2 ​​performs a second round of security detection.

[0236] After the security check is passed, Bob'2 extracts the authentication photon. Based on the measurement of Bob'2's authentication photon, Bob'2 selects a diagonal basis (X basis) and another diagonal basis (X basis) to measure the authentication photon. Bob'2 obtains the measurement results |-> and |+> and publishes the results. Alice authenticates Bob'2's identity based on the published results. If Bob'2 is an unauthorized user, this situation is the same as if Bob'1 were an unauthorized user.

[0237] After successful authentication, the sequence of a single photon is as follows:

[0238]

[0239] According to Bob′2’s information encoding rules, Bob′2 ​​sequentially performs unitary operations on the spatial degrees of freedom of the information transmission photons. and Forming a single-photon sequence S3:

[0240]

[0241] Bob′2 ​​randomly inserts a single photon, randomly encoded in two degrees of freedom, as a security detection photon, and randomly inserts it into S3 to form S′3. Bob′2 ​​then sends S′3 to Alice. After Alice receives all the photons, Bob′2 ​​announces the position of the security detection photon and the quantum state of the two degrees of freedom, and Alice performs a third round of security checks.

[0242] After passing the security test, Alice, based on the information from the preparation process, selected a measurement basis to measure the two degrees of freedom of the information-transmitting photon. According to Alice's decoding rules, she compared the quantum states of sequence S3 and S1. Alice could then determine that Bob's unitary operations on polarization freedom were as follows: and Bob'2's unitary operations on space freedom are as follows: and That is, the information transmitted by Bob′1 is 110 and the information transmitted by Bob′2 ​​is 010.

[0243] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0244] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0245] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0246] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0247] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1.A three-party quantum secure direct communication method with identity authentication function, characterized in that, The method comprises the following steps: The receiver Alice prepares a sequence of photons and sends it to the actual communication partner and publishes the sequence of photons and the positions and quantum states of the security detection photons In response to the sequence of photons sent by the receiver Alice and the published sequence of photons detecting the position and quantum state of the secure photons, the actual communicator performs the first round of security detection and publishes; In response to the actual communication party The first round of published security detection by information, the receiving party Alice publishes a photon sequence The identity authentication photon of the target sender The position of the identity authentication photon; In response to the sequence of photons published by the receiver Alice The identity of the middle target sender The location of the identity authentication photons, the actual communication party Carries out identity authentication photon measurement and publishes; in response to the actual communication party publishing the identity authentication photon measurement result, the receiving party Alice performs identity authentication on the actual communication party , and if the identity authentication is passed, the actual communication party is determined as the target sender and is published, and the position of the identity authentication photon of the target sender in the published photon sequence is published. in response to the actual communicating party authentication through information and photon sequence of the middle target sender authentication photon position, actual communicating party update photon sequence generate photon sequence and send to actual communicating party , and publish photon sequence safe detection photon position and quantum state; actual communicating party transmitted photon sequence and published photon sequence detecting the position and quantum state of the security photons, actual communicating party performing a second round of security detection, and if the second round of security detection passes, performing identity authentication photon measurement and publishing in response to the actual communication party publishing the identity authentication photon measurement result, the receiving party Alice performs identity authentication on the actual communication party , and if the identity authentication is passed, the actual communication party is determined as the target sending party and published in response to the actual communicating party announced by the receiver Alice identity authentication passing information, the actual communicating party updating the photon sequence generating the photon sequence and sending to the receiver Alice, and announcing the photon sequence detecting the position and quantum state of the photon in security in response to the actual communication party transmitted photon sequence and the published photon sequence detect the position and quantum state of the security detection photon in the decode the information transmission photon in the photon sequence to obtain the transmission information. 2.The three-party quantum secure direct communication method with identity authentication function according to claim 1, wherein, The sequence of photons The preparation process comprises: randomly preparing a plurality of single photons super-encoded in polarization-spatial degrees of freedom as information transmission photons, and generating a photon sequence according to the information transmission photons ; According to the identity code of the target sender and corresponding number of single photons encoded in the polarization degree of freedom as identity authentication photons are prepared, and the identity authentication photons are randomly inserted into the photon sequence The photon sequence is generated ; A plurality of single photons super-encoded in polarization-spatial degrees of freedom are randomly prepared as secure detection photons, and the secure detection photons are randomly inserted into a photon sequence The photon sequence is generated in the middle ; Wherein, the identity code of the target sender and is a set of random key sequences shared by the receiver Alice respectively with the target sender and . and . 3.The three-party quantum secure direct communication method with identity authentication function according to claim 2, wherein, The key sequence And By sharing through the BB84 protocol, the key sequence And Respectively: In the formula, Key sequences and The Middle One key bit, This represents the number of key bits. 4.The three-party quantum secure direct communication method with identity authentication function according to claim 3, wherein, The preparation of a plurality of single photons super-encoded in polarization-space degrees of freedom comprises: For the polarization freedom of the single photon, a corresponding quantum state is prepared: wherein horizontal, vertical polarization states of the photons; For the spatial freedom of the single photon, a corresponding quantum state is prepared: In the formula, for a photon to travel along a path propagation; According to the quantum state of the single photon in the polarization freedom and the spatial freedom, a quantum state super-encoded in the polarization-space degrees of freedom is formed: 5.The three-party quantum secure direct communication method with identity authentication function according to claim 3, wherein, The identity code of the target sender and preparing a corresponding number of single photons encoded in a polarization degree of freedom. According to each key in the identity code, the corresponding single photon is prepared in turn: when the key bit of the identity code of the target sender is 0, a single photon with quantum state is prepared by using the orthogonal basis . ​​ When the identity code of the target sender or is 1, a single photon with a quantum state prepared by a diagonal basis is used; wherein, , , , , . 6.The three-party quantum secure direct communication method with identity authentication function according to claim 4, wherein, the actual communication party performing the first round of security detection comprises: extracting the security detection photons from the photon sequence the position of the security detection photons from the photon sequence extracting the security detection photons from the photon sequence According to the published photon sequence The quantum state of the security detection photon is detected, and a measurement base is selected for each security detection photon in the polarization and spatial freedom. If the quantum state of the security detection photon in the polarization degree of freedom is , the selected measurement basis is the orthogonal basis, and if the quantum state of the security detection photon in the polarization degree of freedom is , the selected measurement basis is the diagonal basis. If the quantum state of the security detection photon in the spatial degree of freedom is the selected measurement basis is the orthogonal basis, and if the quantum state of the security detection photon in the spatial degree of freedom is the selected measurement basis is the diagonal basis. According to the selected measurement base, each security detection photon is measured in the polarization degree of freedom and the spatial degree of freedom respectively, and the measurement results are matched with the published photon sequence The quantum state of the security detection photon is matched in consistency. According to the consistency matching result, the security detection error rates in the polarization freedom and the spatial freedom are respectively calculated, and if the security detection error rates in the polarization freedom and the spatial freedom are both lower than the corresponding error rate thresholds, the first round of security detection is passed. 7.The three-party quantum secure direct communication method with identity authentication function according to claim 3, wherein, the actual communicating party performing the identity authentication photon measurement comprises: extracting the identity authentication photon of the target sender from the photon sequence according to the published photon sequence the identity authentication photon of the target sender from the photon sequence extracting the identity authentication photon of the target sender from the photon sequence according to the published photon sequence the identity authentication photon of the target sender According to the actual communication party The identity code of itself, and the measurement bases are selected for the identity authentication photons respectively: When the actual communication party The first in the identity code key bits When the value is 0, the selected measurement basis is a right-angled basis; When the actual communication party The first in the identity code key bits When the value is 1, the selected measurement basis is the diagonal basis; According to the selected measurement basis, each identity authentication photon is measured in the polarization freedom. The receiver Alice authenticates the actual communication party includes authenticating the identity of the actual communication party According to the actual communication party Published identity authentication photon measurement results and photon sequences Intermediate target sender The quantum state of the identity authentication photon is matched consistently; According to the consistency matching result, the identity authentication error rate is calculated, and if the identity authentication error rate is lower than the corresponding error rate threshold, the identity authentication is passed. 8.The three-party quantum secure direct communication method with identity authentication function according to claim 1, wherein, the actual communication party updating the photon sequence generating the photon sequence comprising: According to the published sequence of photons In the target sender And The identity of the photons, the location of the security detection photons, determine the sequence of photons In the location of the information transmission photons; According to the position of the information-carrying photons in the photon sequence the information-carrying photons in the photon sequence the information-carrying photons in the photon sequence Each information transmission photon is encoded in its polarization freedom: When the actual communication party The secret information to be transmitted is 0, and the selected Performing a unitary operation on the quantum state: wherein , ; When the actual communication party The secret information to be transmitted is 1, and the selected Performing a unitary operation on the quantum state: The photon sequence is recorded as photon sequence The identity authentication photon is extracted, and the photon sequence after encoding the information transmission photon is recorded as photon sequence ;​ A plurality of single photons super-encoded in polarization-spatial degrees of freedom are randomly prepared as secure detection photons, and the secure detection photons are randomly inserted into a photon sequence The photon sequence is generated in the middle . 9.The three-party quantum secure direct communication method with identity authentication function according to claim 1, wherein, the actual communication party updating the photon sequence generating the photon sequence comprising: According to the published photon sequence mid-target sender The location of the identity authentication photon and the published photon sequence The location of photons is detected in the middle security system to determine the photon sequence. The location of the photons transmitting information; According to the position of the information-carrying photons in the photon sequence determining the information-carrying photons in the photon sequence determining the information-carrying photons in the photon sequence Each information transmission photon is encoded in its spatial freedom: When the actual communication party The secret information to be transmitted is 0, and the selected Perform a unitary operation on the quantum state: wherein , ; When the actual communication party The secret information to be transmitted is 1, and the selected Perform a unitary operation on the quantum state: sequence of photons China Security Detection Photons and Target Senders After the identity authentication photons are extracted, and the photon sequence encoded by the information transmission photons is denoted as the photon sequence, it is recorded as a photon sequence. ; A plurality of single photons super-encoded in polarization-spatial degrees of freedom are randomly prepared as secure detection photons, and the secure detection photons are randomly inserted into a photon sequence The photon sequence is generated in the middle . 10.The three-party quantum secure direct communication method with identity authentication function according to claim 1, wherein, The receiver Alice decodes to obtain the transmission information, comprising: According to the published sequence of photons The position of the security photons is detected in the middle The position of the information photons is transmitted in the middle According to the sequence of photons the position of the information-carrying photon from the sequence of photons extracting the information-carrying photon; According to the photon sequence The initial quantum state of the information transmission photon, the photon sequence Each information transmission photon extracted in the middle selects a corresponding measurement base in the polarization degree of freedom and the spatial degree of freedom, respectively; Extracting information from a sequence of photons according to a selected measurement basis Each information-carrying photon is measured in a polarization degree of freedom and a spatial degree of freedom. According to the measurement result and the photon sequence The quantum state of each information transmission photon is compared, and the actual communication party And The encoding information is transmitted as the transmission information of the target sender And The encoding information is transmitted as the transmission information of the target sender

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