Continuous variable quantum secret sharing method

Abstract

The invention discloses a continuous variable quantum secret sharing method, and relates to the field of quantum communication. The method specifically comprises the following steps: firstly, constructing a communication scene; each of the n participants and the distributor comprises s quantum modules and t classic modules; then, grouping all quantum modules and classic modules; then, selecting from the participants one by one, randomly selecting the grouping number of classic modules from the s quantum modules for each participant, respectively sending the quantum state Sir to each classic module of each participant, performing recovery and classic post-processing by adopting a VSS protocol to obtain s groups of keys of each participant, and performing splicing and private key amplification to obtain s groups of keys of each participant; the final secret key of each participant is obtained, and sharing between each participant and the secret key distributed by the distributor is realized. According to the invention, multiple quantum modules are combined with a private key amplification technology, and multiple classic modules are combined with a VSS technology, so that hacker attacks of an eavesdropper on non-ideal quantum modules and non-ideal classic modules in a quantum secret sharing protocol can be resisted.

Description

Technical Field

[0001] The invention relates to the technical field of quantum communication, and in particular to a continuous variable quantum secret sharing method. Background Art

[0002] Private key amplification technology (SIAM J. Comput. 17, 210–229) is a technology that uses a hash algorithm to compress the key. It can remove part of the key information obtained by the eavesdropper and generate a secure key.

[0003] Verifiable Secret Sharing (VSS) technology (Discrete Appl. Math. 154, 370-38) is a secure multi-party communication technology in classical cryptography. It can securely distribute and reconstruct secrets when there are a certain number of dishonest parties in a group.

[0004] Quantum Secret Sharing (QSS) is a practical multi-party quantum communication technology that combines quantum physics and classical information theory to achieve unconditionally secure secret sharing through quantum means. In the quantum secret sharing protocol, the distributor (dealer) and the participant (player) of the protocol prepare quantum states through quantum modules (including lasers, modulators and other devices) in the local security station, and then send the quantum state information to the classical module, which completes the classical post-processing process and finally obtains the same secret.

[0005] The earliest quantum secret sharing protocol was first proposed by Hillery et al. in 1999 (Phys. Rev. A 59, 1829). The protocol used GHZ entangled states to ensure the security of secret sharing. In order to improve the practicality of quantum secret sharing, Schmid et al. (Phys. Rev. Lett. 95, 230505) proposed a single-photon sequential quantum secret sharing protocol in 2005. This protocol did not use the entanglement property, but used all participants to perform polarization rotation on the same photon to complete secret sharing, thus greatly reducing the difficulty of implementing the system.

[0006] In the field of continuous variables, in 2018 Grice et al. (Phys. Rev. A100, 02233) proposed a continuous variable quantum secret sharing protocol that does not utilize the properties of entanglement. The distributor and multiple participants generate security keys respectively, thereby realizing (n,n) threshold quantum secret sharing, improving tolerance to noise and loss, and being able to be expanded to situations with a large number of participants, thereby increasing the practicality of quantum secret sharing. Summary of the invention

[0007] On the basis of the existing technology, in order to overcome the defect that quantum secret sharing is easily vulnerable to attacks against non-ideal quantum and classical devices, the present invention provides a continuous variable quantum secret sharing method. Based on the original quantum secret sharing protocol, this method uses multi-quantum modules and multi-classical modules to complete quantum state preparation and classical post-processing processes respectively, and is combined with private key amplification and VSS technology to resist hacker attacks on non-ideal devices by eavesdroppers. At the same time, it will not change other steps of the original protocol, thereby improving the security of quantum secret sharing.

[0008] The continuous variable quantum secret sharing method comprises the following specific steps:

[0009] Step 1: Construct a communication scenario of quantum secret sharing for n participants and 1 distributor;

[0010] Each person consists of s quantum modules and t classical modules; each quantum module is connected to t classical modules; each classical module is connected to the remaining t-1 classical modules;

[0011] Among all people's quantum modules, connect the quantum modules with the same serial number together; connect all the classical modules with the same serial number together, and all connections are connected through a secure channel.

[0012] Step 2: Group all quantum modules of the distributor and n participants, and group all modules with the same serial number into one group;

[0013] All quantum modules are divided into s groups, represented by {Q1,Q2,...Q s}; Each group contains n+1 quantum modules, and the sth group is represented by {Q s1 ,Q s2 ,...Q s(n+1)};

[0014] Step 3: At the same time, each person selects tt′ from his or her own classic modules to obtain Group classic modules;

[0015] t′ represents the number of non-ideal classical modules, and satisfies t′<t / 3;

[0016] Step 4: Select from the participants one by one. For the i-th participant, randomly select r from the s quantum modules, corresponding to r shares of quantum state information S ir ;

[0017] Each quantum module corresponds to its own quantum state information;

[0018] Step 5: Quantum state information S irIt is sent to each classic module of the i-th participant through a secure channel, and the classic module is restored using the VSS distribution protocol and reconstruction protocol;

[0019] Specifically, for the tt′ classical modules of the i-th participant, first, each classical module exchanges the received S ir , determine whether they are all the same, if so, then S ir Send all the classic modules except tt′ classic modules to the i-th participant; otherwise, the scheme terminates;

[0020] Other classic modules continue to exchange the S ir , determine whether S ir Does the number of occurrences exceed If yes, then S ir Correct, otherwise, the program terminates.

[0021] Step 6: Recover the quantum state information S ir After classical post-processing, we get the s group keys of the i-th participant: K1, K2, ..., K s ;

[0022] Each quantum module of the i-th participant corresponds to a set of keys, and the length of each set of keys is N.

[0023] Step 7: The classic module concatenates the s groups of keys to obtain K i ', and amplify the private key to obtain the final key of the i-th participant, and share the key of the i-th participant with the distributor.

[0024] The final key length is (ss′)×N; s′ represents the number of non-ideal quantum module groups;

[0025] Step 8. Return to step 4, select the next participant and obtain the corresponding final key, and finally realize that n participants share the keys distributed to them by the distributor.

[0026] When the number of quantum module groups s′ with non-ideal quantum modules satisfies s′<s and the number of non-ideal classical modules per person t′ satisfies t′<t / 3, the eavesdropper cannot obtain any information of the final key by attacking the non-ideal device.

[0027] The advantages of the present invention are:

[0028] 1) A continuous variable quantum secret sharing method, which uses multiple quantum modules combined with private key amplification technology without changing the original quantum secret sharing protocol, can resist hacker attacks by eavesdroppers on non-ideal quantum modules in the quantum secret sharing protocol.

[0029] 2) A continuous variable quantum secret sharing method that uses multiple classical modules combined with VSS technology can resist hacker attacks from eavesdroppers on non-ideal classical modules in the quantum secret sharing protocol. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A secret sharing scenario consisting of multiple quantum modules and multiple classical modules constructed for the present invention;

[0031] Figure 2 The present invention is a flow chart of a continuous variable quantum secret sharing method. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and implementation examples.

[0033] The present invention uses multiple quantum modules and multiple classical modules to complete the quantum state preparation and classical post-processing process of quantum secret sharing. Assume that n participants and 1 distributor each use s quantum modules and t classical modules in a security station to perform quantum secret sharing, wherein all quantum modules of the participants are grouped to complete the quantum state preparation process, and each person's t classical modules complete the classical post-processing process. When the number of non-ideal quantum module groups s′ satisfies s′<s and the number of non-ideal classical modules per person t′ satisfies t′<t / 3, the method proposed by the present invention can resist attacks against non-ideal devices.

[0034] The continuous variable quantum secret sharing method includes the following steps which can be performed independently: using multiple quantum modules to prepare quantum states and using multiple classical modules to perform classical post-processing; Figure 2 As shown, the specific steps are as follows:

[0035] Step 1: Construct a communication scenario of quantum secret sharing for n participants and 1 distributor;

[0036] like Figure 1 As shown, each person includes s quantum modules and t classical modules; each quantum module is connected to t classical modules; each classical module is connected to the remaining t-1 classical modules;

[0037] Among all people's quantum modules, connect the quantum modules with the same serial number together; connect all classical modules with the same serial number together, and all connections are connected through a secure channel (that is, a channel that cannot be eavesdropped).

[0038] Step 2: Group all quantum modules of the distributor and n participants, and group all modules with the same serial number into one group;

[0039] All quantum modules are divided into s groups according to their serial numbers, represented as {Q1,Q2,...Qs}; Each group contains n+1 different quantum modules corresponding to the same serial number, and the sth group is represented by {Q s1 ,Q s2 ,...Q s(n+1)};

[0040] Each quantum module corresponds to its own quantum state information;

[0041] Step 3: At the same time, the distributor and n participants each randomly select tt′ from their own t classic modules to obtain Group classic modules;

[0042] t′ represents the number of non-ideal classical modules, and satisfies t′<t / 3; each person randomly selects tt′ different modules into a group, so everyone has

[0043] Step 4: Select from the participants one by one. For the i-th participant, randomly select r from the s quantum modules, corresponding to r shares of quantum state information S ir ;

[0044] Step 5: Quantum state information S ir It is sent to each classical module of the i-th participant through a secure channel, and the classical module uses the VSS distribution protocol and VSS reconstruction protocol to recover the initial quantum state information.

[0045] The VSS distribution protocol will be S ir It is sent to each classical module separately, and each classical module is reconstructed using the VSS reconstruction protocol. Finally, each classical module restores the initial quantum state information.

[0046] Specifically, for the tt′ classical modules of the i-th participant, first, each classical module exchanges the received S ir , determine whether they are all the same, if so, then S ir Send all the classic modules except tt′ classic modules to the i-th participant; otherwise, the scheme terminates;

[0047] Other classic modules continue to exchange the S ir , judge S ir Does the number of occurrences exceed If yes, then S ir Correct, otherwise, the program terminates.

[0048] Step 6: Recover the quantum state information S ir After classical post-processing, we get the s group keys of the i-th participant: K1, K2, ..., K s ;

[0049] Each quantum module of the i-th participant corresponds to a set of keys, and the length of each set of keys is N.

[0050] Step 7: The classic module concatenates the s groups of keys to obtain K i ', and amplify the private key to obtain the final key of the i-th participant, and share the key of the i-th participant with the distributor.

[0051] The final key length is (ss′)×N; s′ represents the number of non-ideal quantum module groups;

[0052] Step 8. Return to step 4, select the next participant and obtain the corresponding final key, and finally realize that n participants share the keys distributed to them by the distributor.

[0053] Example:

[0054] (1) Group all quantum modules of the distributor and n participants, and group all modules with the same sequence number into one group. Therefore, there are s groups of quantum modules in total, denoted as Q i (i=1,2,...,s); each group contains n+1 quantum modules, denoted as Q ij (j=1,2,...,n+1). At the same time, each person groups his own classic modules, selecting tt′ different modules into a group each time, so everyone has The classical module group corresponding to the jth quantum module is represented by C jk (k=1,2,...,r).

[0055] For example, for the second quantum module Q in group 1 12 ; t is 6, t′ is 1, then every 5 classic modules form a group, and r is 6;

[0056] (2) Each participating quantum module needs to carry out the quantum state preparation process of the original quantum secret sharing protocol, and prepare s groups of quantum states in total; each quantum module of the distributor needs to carry out the quantum state preparation or detection process of the original quantum secret sharing protocol;

[0057] (3) For the jth quantum module Q in the i-th group ij , using VSS distribution protocol to the corresponding C jk Each classical module in distributes quantum state information S ij :

[0058] (4)C jk All classic modules in the system are restored using the VSS reconstruction protocol:

[0059] First Cjk Among the \(t - t'\) classical modules, they exchange the received \(S\) through a secure channel ij and determine whether the \(t - t'\) \(S\)'s ij are all the same. If so, all the classical modules in \(C\) jk send \(S\) to the remaining classical module groups \(C\) ij in the secure station through a secure channel jk′ (where \(k' = 1, 2,\cdots, r\) and \(k' \neq k\)). Otherwise, the scheme terminates;

[0060] The \(t - t'\) classical modules in \(C\) jk′ exchange their received shares with each other again. If the occurrence times of a certain share exceed times, then it is determined to be \(S\) ij .

[0061] (5) Through the above steps, all quantum modules securely send the \(s\) groups of quantum state information to all classical modules in the corresponding secure station. Subsequently, the classical modules use the recovered quantum state information and perform classical post - processing according to the post - processing process of the original quantum secret sharing protocol to finally obtain \(s\) groups of keys \(K_1, K_2,\cdots, K\) s , and the length of each group of keys is \(N\).

[0062] (6) The classical modules splice the \(s\) groups of keys to obtain \(K=[K_1, K_2,\cdots, K\) s , and perform private key amplification on it to obtain the final key with a length of \((s - s')\times N\). When the number of groups of quantum modules with non - ideal quantum modules \(s'\) satisfies \(s' \lt s\) and the number of non - ideal classical modules per person \(t'\) satisfies \(t' \lt t / 3\), the eavesdropper cannot obtain any information about the final key through attacks against non - ideal devices.

Claims

1. A continuous variable quantum secret sharing method, characterized in that: The specific steps are as follows: Step 1: Construct a communication scenario of quantum secret sharing for n participants and 1 distributor; Each one consists of s quantum modules and t classical modules; Step 2: Group all quantum modules of the distributor and n participants, and group all modules with the same serial number into one group; Step 3: At the same time, each person selects tt′ from his or her own classic modules to obtain Group classic modules; t′ represents the number of non-ideal classical modules, and satisfies t′<t / 3; Step 4: Select from the participants one by one. For the i-th participant, randomly select r from the s quantum modules, corresponding to r shares of quantum state information S ir ; Each quantum module corresponds to its own quantum state information; Step 5: Quantum state information S ir It is sent to each classic module of the i-th participant through a secure channel, and the classic module is restored using the VSS distribution protocol and reconstruction protocol; Specifically, for the tt′ classical modules of the i-th participant, first, each classical module exchanges the received S ir , determine whether they are all the same, if so, then S ir Send to the i-th participant all the classic modules except tt′ classic modules; Otherwise, the plan is terminated; Other classic modules continue to exchange the S ir , determine whether S ir Does the number of occurrences exceed If yes, then S ir Correct, otherwise, the program terminates; Step 6: Recover the quantum state information S ir After classical post-processing, we get the s group keys of the i-th participant: K1, K2, ..., K s ; Step 7: The classic module concatenates the s groups of keys to obtain K i ', and amplify the private key to obtain the final key of the i-th participant, and share the key of the i-th participant with the distributor; The final key length is (ss′)×N; s′ represents the number of non-ideal quantum module groups; Step 8. Return to step 4, select the next participant and obtain the corresponding final key, and finally realize that n participants share the keys distributed to them by the distributor.

2. A continuous variable quantum secret sharing method as claimed in claim 1, characterized in that: In the communication scenario described in step 1, each quantum module is connected to t classical modules respectively; each classical module is connected to the remaining t-1 classical modules respectively; Among all people's quantum modules, connect the quantum modules with the same serial number together; connect all the classical modules with the same serial number together, and all connections are connected through a secure channel.

3. A continuous variable quantum secret sharing method as claimed in claim 1, characterized in that: In step 2, all quantum modules are divided into s groups, represented by {Q1, Q2, ... Q s }; Each group contains n+1 quantum modules, and the sth group is represented by {Q s1 ,Q s2 ,...Q s(n+1) }.

4. A continuous variable quantum secret sharing method as claimed in claim 1, characterized in that: In step 6, each quantum module of the i-th participant corresponds to a set of keys, and the length of each set of keys is N.

5. A continuous variable quantum secret sharing method as claimed in claim 1, characterized in that: In step eight, when the number of quantum module groups s′ with non-ideal quantum modules satisfies s′<s, and the number of non-ideal classical modules per person t′ satisfies t′<t / 3, the eavesdropper cannot obtain any information of the final key by attacking the non-ideal device.

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