Bidirectional secret information exchange method based on unidirectional quantum channel

Abstract

The invention provides a bidirectional secret information exchange method based on a unidirectional quantum channel, and belongs to the technical field of quantum communication. The problem of information loss in the current bidirectional quantum communication is solved; alice randomly prepares n six-particle cluster states, and divides the six-particle cluster states into six particle sequences; alice randomly selects decoy particles from the four decoy quantum states, randomly inserts the decoy particles into a third particle sequence and a fourth particle sequence, and records the initial states and positions of the decoy particles; then, sending to Bob through a one-way quantum channel; when Bob receives a sequence containing decoy particles, Alice publishes the initial state and position of the decoy particles, and Bob selects a correct measurement base to measure the decoy particles to check whether eavesdropping exists or not; quantum logic gate operation and coding are carried out on the two; performing decryption; authentication and verification; according to the invention, bidirectional encryption communication on a unidirectional quantum channel is realized by using a six-particle cluster state.

Description

Technical Field

[0001] The invention provides a bidirectional secret information exchange method based on a one-way quantum channel, belonging to the technical field of quantum communication. Background Art

[0002] Nowadays, the transmission and exchange of information has become more convenient, but the problems of information security and privacy protection have become more important. With the development of quantum computing, traditional classical cryptographic algorithms based on mathematical difficulty assumptions are facing the potential threat of being cracked. Quantum communication, based on the basic characteristics of quantum mechanics, provides a new solution for achieving information security.

[0003] In existing research on quantum bidirectional secret information exchange, the quantum channels in most algorithms are bidirectional, that is, quantum bits must be transmitted twice in the quantum channel to achieve "forward" and "return" transmission. Bidirectional quantum channels not only increase the risk of quantum bit and information loss, but also rely on wavelength filter photon number splitters to a certain extent to resist Trojan horse attacks. In addition, even in research on quantum bidirectional secret information exchange with identity authentication, most algorithms still lack information verification mechanisms, which may cause attackers to tamper with information through classical channels, thereby causing the risk of errors in secret information transmission. Therefore, it is necessary to design a bidirectional secret information exchange algorithm based on a one-way quantum channel with identity authentication and secret information verification mechanisms. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a bidirectional secret information exchange method based on a one-way quantum channel, and realizes bidirectional encrypted communication on the one-way quantum channel by using a six-particle cluster state.

[0005] The technical solution adopted by the present invention is: a bidirectional secret information exchange method based on a one-way quantum channel, comprising the following steps:

[0006] Step 1: Alice randomly prepares n six-particle cluster states Among them, r∈{1,2}, i=1,2,3,…,n, and these six-particle cluster states are divided into six particle sequences Where j = 1, 2, 3, 4, 5, 6, is the jth particle of the i-th six-particle cluster state;

[0007] Step 2: Alice randomly selects decoy particles from the four quantum states {|0>, |1>, |+>, |->} and inserts them into S3 and S4 to obtain S′3 and S′4, and records the initial states and positions of these decoy particles; then, Alice sends S′3 and S′4 to Bob;

[0008] Step 3: When Bob receives S′3 and S′4, Alice announces the initial state and position of the decoy particle, and Bob selects the correct measurement basis to measure the decoy particle; if the error rate of the decoy particle is higher than the predetermined threshold, the communication is considered unsafe; if the error rate of the decoy particle is lower than the predetermined threshold, Bob removes the decoy particle to obtain S3 and S4; then, Alice uses the Bell basis to measure and record the results;

[0009] Step 4: Bob chooses Operations on particles Get And use Bell basis measurement Get the measurement result |φ x > i , according to all |φ x > i , Bob encodes in

[0010] Step 5: Bob makes inferences based on the set rules The state is encoded as MB = (mb1, mb2, ..., mb i ,…,mb n )∈{00,01,10,11} n , where mb i =|φ x > i = x, then Bob calculates the encryption key K b =H(K||MB) and encrypted message and announce to Alice; K is the identity authentication key shared by Alice and Bob, H() is the hash function, E * (·) is a one-time pad encryption algorithm, * represents the key, · represents the information to be encrypted;

[0011] Step 6: Alice chooses Operations on particles Get And use Bell basis measurement Get the measurement result |φ x > i , according to all |φ x > i , Alice encodes in

[0012] Step 7: Alice infers based on the set rules The state is encoded as MA=(max1, ma2, ..., ma i ,…,ma n )∈{00,01,10,11} n , where ma i =|φ x > i = x; Then, Bob calculates the encryption key K a =H(K||MA) and encrypted message and announce To Bob;

[0013] Step 8: Decryption, Alice calculates K b =H(K||MB) and use K b Decryption get Depend on Get Bob's secret information B; Bob calculates K a =H(K||MA) and use K a Decryption get Depend on Get Alice's secret information A;

[0014] Step 9: Authentication and verification. Alice and Bob calculate and publish hash values ​​H(B) and H(A) respectively for both parties to authenticate each other and verify whether each other's secret information is correct.

[0015] Steps 4 and 6 operate, The operation is four quantum logic gate operations, where: U 00 =I;U 01 =Z;U 10 =X;U 11 =Y;

[0016] I=|0><0|+|1><1|;

[0017] Z=|0><0|-|1><1|;

[0018] X=|0><1|+|1><0|;

[0019] Y=|0><1|-|1><0|.

[0020] The setting rules in steps 5 and 7 are shown in the following table:

[0021]

[0022] Alice and The Bell basis measurement results determine mb i .

[0023] Bob The Bell basis measurement results determine ma i .

[0024] Alcie's secret information: A = (a1, a2, ..., a n )∈{00,01,10,11} n , Bob’s secret information: B = (b1, b2, …, b n )∈{00,01,10,11} n , Alice and Bob share the authentication key: K = (k1, k2, ..., k n )∈{00,01,10,11} n .

[0025] The beneficial effects of the present invention compared with the prior art are as follows:

[0026] 1. Use a one-way quantum channel and only need to transmit the quantum bit once, which relatively reduces the loss of quantum bits and classical information during transmission;

[0027] 2. Both parties can exchange their secret information securely by executing the complete algorithm once.

[0028] 3. It has identity authentication and secret information verification mechanisms, making the scheme more robust. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings:

[0030] Figure 1 Circuit diagram for preparing two six-particle cluster states;

[0031] Figure 2 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0032] like Figure 1-2 As shown, the present invention provides a bidirectional secret information exchange method based on a one-way quantum channel. The meanings of the initial data and some parameters used in the method are as follows:

[0033] 1. Initial data includes:

[0034] 1) Secret information of participant Alcie: A = (a1, a2, ..., a n )∈{00,01,10,11} n .

[0035] 2) Party Bob’s secret information: B = (b1, b2, …, b n )∈{00,01,10,11} n .

[0036] 3) Identity authentication key shared by Alice and Bob: K = (k1, k2, ..., k n )∈{00,01,10,11} n .

[0037] 2. Parameter descriptions are as follows:

[0038] H(): {00, 01, 10, 11} * →{00,01,10,11} n is a hash function;

[0039] || is the classic bit string concatenation operation;

[0040] E * (·) is a one-time pad encryption algorithm, * represents the key, · represents the information to be encrypted;

[0041] ⊕ is the XOR operation;

[0042] The six-particle cluster state is represented as:

[0043]

[0044] Four Bell states |φ x >(x∈{00,01,10,11}n is expressed as:

[0045]

[0046] The four quantum logic gate operations are represented as:

[0047] I=|0><0|+|1><1|;

[0048] Z=|0><0|-|1><1|;

[0049] X=|0><1|+|1><0|;

[0050] Y=|0><1|-|1><0|.

[0051] The four U operations are represented as:

[0052] U 00 =I;U 01 =Z;U 10 =X;U 11 =Y.

[0053] The implementation steps of the method of the present invention are as follows:

[0054] Step 1: Alice randomly prepares n six-particle cluster states Among them, r∈{1,2}, i=1,2,3,…,n. Then, Alice divides these six-particle cluster states into six particle sequences Where j = 1, 2, 3, 4, 5, 6, is the jth particle of the i-th six-particle cluster state. Figure 1 The circuit diagram for preparing two six-particle cluster states is shown in the figure. It is the Hadamard gate. not =(|00><00|+|01><01|+|10><11|+|11><10|) 12 It is a controlled NOT gate, where the small circle is the target bit and the large circle is the control bit. For the six quantum states with the initial state of |0>, through the quantum gates in the action diagram, the corresponding six-particle cluster state is finally obtained. In the figure, X is X in the four quantum logic gate operations.

[0055] Step 2: Alice randomly selects decoy particles from the four quantum states {|0>, |1>, |+>, |->} and inserts them into S3 and S4 to obtain S′3 and S′4, and records the initial states and positions of these decoy particles. Then, Alice sends S′3 and S′4 to Bob.

[0056] S3 and S4 are sent from Alice to Bob through the quantum channel, and the decoy particles are inserted to prevent eavesdropping. However, S1, S2, S5 and S6 do not need to be sent to Bob, but only in Alice's hands.

[0057] Step 3: When Bob receives S′3 and S′4, Alice announces the initial state and position of the decoy particle. Bob selects the correct measurement basis to measure the decoy particle. If the error rate of the decoy particle is higher than the predetermined threshold, the communication is considered unsafe. If the error rate of the decoy particle is lower than the predetermined threshold, Bob removes the decoy particle and obtains S3 and S4. Then, Alice uses the Bell basis to measure And record the results.

[0058] Step 4: Bob chooses Operations on particles Get And use Bell basis measurement Get the measurement result |φ x > i . According to all |φ x > i , Bob encodes in

[0059] where b i It is the i-th bit (i=1, 2, 3, ..., n) of Bob's secret information B in the initial data. It is one of the four U operations. For example, b i =00, then b i =11, then

[0060] where |φ x > i The i in is the index, which means the i-th one. Here it means the i-th The measurement result of , x is which of the four Bell states the ith measurement result is. For example, x = 00, which means the measurement result is the first Bell state, that is

[0061] in is the classical correspondence of all Bell state measurement results. For example, the i-th The measurement result is the first of the four Bell states, that is, x = 00, then the i-th yes A collection of .

[0062] Step 5: Bob infers based on Table 1 The state is encoded as MB = (mb1, mb2, ..., mb i ,…,mb n )∈{00,01,10,11} n , where mb i =|φ x > i = x. Then, Bob calculates the encryption key K b =H(K||MB) and used to encrypt the message in encryption algorithm E and announce To Alice.

[0063]

[0064] Table 1. Results of Alice and Bob’s encoding and operations.

[0065] Step 6: Alice chooses Operations on particles Get And use Bell basis measurement Get the measurement result |φ x > i . According to all |φx > i , Alice encodes in

[0066] Step 7: Alice infers based on Table 1 The state is encoded as MA=(ma1, ma2, …, ma i ,…,ma n )∈{00,01,10,11} n , where ma i =|φ x > i =x. Then, Alice calculates K a =H(K||MA) and and announce To Bob.

[0067] Step 8: Decryption, Alice calculates K b =H(K||MB) and use K b Decryption get Depend on Get Bob's secret information B. Bob calculates K a =H(K||MA) and use K a Decryption get Depend on Get Alice's secret information A. Note: Alice based on and The Bell basis measurement results can determine mb i , Bob based The Bell basis measurement results can determine ma i .

[0068] Step 9: Authentication and verification. Alice and Bob calculate and publish H(B) and H(A) respectively for both parties to authenticate each other and verify whether each other's secret information is correct.

[0069] H(B) is the hash value of Bob's secret information calculated by Alice. H(A) is the hash value of Alice's secret information calculated by Bob. Both parties use the hash value to confirm whether the secret information received from the other party is correct and whether the correct identity authentication key is used.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bidirectional secret information exchange method based on a one-way quantum channel, characterized in that: The following steps are involved: Step 1: Alice randomly prepares n six-particle cluster states Among them, r∈{1,2}, i=1,2,3,…,n, and these six-particle cluster states are divided into six particle sequences Where j = 1, 2, 3, 4, 5, 6, is the jth particle of the i-th six-particle cluster state; Step 2: Alice randomly selects decoy particles from the four quantum states {|0>, |1>, |+>, |->} and inserts them into S3 and S4 to obtain S′3 and S′4, and records the initial states and positions of these decoy particles; then, Alice sends S′3 and S′4 to Bob; Step 3: When Bob receives S′3 and S′4, Alice announces the initial state and position of the decoy particle, and Bob selects the correct measurement basis to measure the decoy particle; if the error rate of the decoy particle is higher than the predetermined threshold, the communication is considered unsafe; if the error rate of the decoy particle is lower than the predetermined threshold, Bob removes the decoy particle to obtain S3 and S4; then, Alice uses the Bell basis to measure and record the results; Step 4: Bob chooses Operations on particles Get And use Bell basis measurement Get the measurement result |φ x > i , according to all |φ x > i , Bob encodes in Step 5: Bob makes inferences based on the set rules The state is encoded as MB = (mb1, mb2, ..., mb i ,…,mb n )∈{00,01,10,11} n , where mb i =|φ x > i = x, then Bob calculates the encryption key K b =H(K||MB) and encrypted message and announce to Alice; K is the identity authentication key shared by Alice and Bob, H() is the hash function, E * (·) is a one-time pad encryption algorithm, * represents the key, · represents the information to be encrypted; Step 6: Alice chooses Operations on particles Get And use Bell basis measurement Get the measurement result |φ x > i , according to all |φ x > i , Alice encodes in Step 7: Alice infers based on the set rules The state is encoded as MA=(ma1, ma2, ..., ma i ,…,ma n )∈{00,01,10,11} n , where ma i =|φ x > i = x; Then, Bob calculates the encryption key K a =H(K||MA) and encrypted message and announce To Bob; Step 8: Decryption, Alice calculates K b =H(K||MB) and use K b Decryption get Depend on Get Bob's secret information B; Bob calculates K a =H(K||MA) and use K a Decryption get Depend on Get Alice's secret information A; Step 9: Authentication and verification. Alice and Bob calculate and publish hash values ​​H(B) and H(A) respectively for both parties to authenticate each other and verify whether each other's secret information is correct.

2. A bidirectional secret information exchange method based on a one-way quantum channel according to claim 1, characterized in that: Steps 4 and 6 operate, The operation is four quantum logic gate operations, where: U 00 =I;U 01 =Z;U 10 =X;U 11 =Y; I＝|0><0|+|1><1|； Z＝|0><0|-|1><1|； X＝|0><1|+|1><0|； Y＝|0><1-|1><0|。 3. The method for bidirectional secret information exchange based on a one-way quantum channel according to claim 1, characterized in that: The setting rules in steps 5 and 7 are shown in the following table:

4. A bidirectional secret information exchange method based on a one-way quantum channel according to claim 3, characterized in that: Alice and The Bell basis measurement results determine mb i .

5. The method for bidirectional secret information exchange based on a one-way quantum channel according to claim 3, characterized in that: Bob The Bell basis measurement results determine ma i .

6. A bidirectional secret information exchange method based on a one-way quantum channel according to claim 1, characterized in that: Alcie's secret message: A=(a1, a2, ..., a n )∈{00,01,10,11} n , Bob’s secret information: B = (b1, b2, …, b n )∈{00,01,10,11} n , Alice and Bob share the authentication key: K = (k1, k2, ..., k n )∈{00,01,10,11} n .

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