Phase coding-based third-party quantum-free multi-party privacy set intersection method and application

Abstract

The invention discloses a phase coding-based non-third-party quantum multi-party privacy set intersection method and application, and belongs to the technical field of quantum privacy calculation. An existing quantum private set intersection scheme mostly aims at a two-party scene or depends on a third party to realize confidential intersection, and potential safety hazards are easily caused by constructing a trusted third party in practical application. In order to solve the problem, the invention provides a quantum intersection protocol for multiple participants, and the protocol effectively realizes intersection calculation of private sets of the participants through a quantum state phase encoding technology. And meanwhile, comprehensive correctness and security analysis is performed on the protocol, and the feasibility and security of the protocol are verified through a Qiskit simulation protocol core process. The method not only can efficiently solve the problem of intersection of multi-party private sets and obtain public elements on the premise of protecting the privacy of each party, but also can be used as a basic module in a multi-party cooperative computing application scene, and is wide in application range.

Description

Technical Field

[0001] This invention belongs to the field of quantum cryptography and multi-party secure computation technology, specifically relating to a phase-encoded method and operating system for finding intersections of quantum multi-party privacy sets without a third party. Background Technology

[0002] With the increasing demand for data sharing and collaboration, how to effectively perform data computation while ensuring privacy protection has become a critical issue. Private Set Interscience (PSI) technology, as one of the core foundational protocols of Secure Multiparty Computation (SMC), enables multiple participants to jointly compute the intersection of all sets without disclosing non-intersecting elements in their respective sets. This achieves collaborative data processing while strictly protecting privacy and security, and has been applied in several important scenarios such as anonymous authentication, privacy-preserving conditional queries, and vertical federated learning.

[0003] In recent years, with the rapid development of quantum computing technology, traditional cryptographic protocols and their secure applications, which rely on the complexity of mathematical problems, are facing increasingly severe quantum threats. To address this challenge, researchers have successively proposed privacy computing schemes based on quantum technology, with Quantum Private Set Intersection (QPSI) being one of the most studied areas. Existing QPSI research mainly focuses on the design of two-party protocols, proposing various theoretical models based on server-client, quantum oblivious transmission, single-particle measurement, and quantum Fourier transform. However, these protocols generally suffer from high implementation complexity, requiring special quantum operations or quantum state encoding, which severely limits their practical deployment feasibility. In addition, some schemes have been found to have security vulnerabilities, such as the risk of malicious servers tampering with the intersection results and potential leakage of private information.

[0004] To enhance the security and practicality of protocols, subsequent research has attempted to introduce trusted third parties (TTPs) or improve coding and measurement methods, such as employing Hadamard gate operations and quantum threshold protocols. While these methods have improved resistance to malicious behavior to some extent, the assumption of trusted third parties is often difficult to meet in practical applications, and most solutions still cannot completely solve the problems of collusion attacks and single points of failure.

[0005] In recent years, the Quantum Multi-Party Privacy Set Intersection (QMPSI) protocol has gradually attracted attention, and existing research has proposed different implementation methods based on semi-honest third parties and quantum greatest common divisor calculation. However, most existing QMPSI schemes still rely on third-party entities, failing to fundamentally solve the dependence on centralized architecture, and also generally face the security threat of collusion between neighboring participants to leak private information. Therefore, constructing a quantum multi-party privacy set intersection protocol that does not require third-party participation, is resistant to collusion attacks, and is easy to implement remains a key problem that urgently needs to be solved.

[0006] Therefore, we propose a novel multi-party quantum privacy set intersection protocol that does not rely on third parties, employing a phase encoding method to compute the privacy set intersection among multiple parties. This protocol improves practical feasibility while effectively reducing implementation complexity and enhancing defense against collusion attacks. Summary of the Invention

[0007] Purpose of the Invention: Addressing the issues of existing quantum privacy set intersection protocols relying on third parties and being primarily focused on two-party scenarios, this invention proposes a third-party-free quantum multi-party privacy set intersection method based on phase encoding. This method aims to enable multiple participants to securely and efficiently compute set intersections without the need for a trusted third party, while also possessing resistance to internal and external attacks. Furthermore, regarding the protocol built using this method, this invention also proposes a medical data sharing system based on a phase-encoded third-party-free quantum multi-party privacy set protocol.

[0008] Technical Solution: This invention provides a phase-encoded, third-party-free quantum multi-party privacy set intersection method. This method utilizes quantum state phase encoding technology to enable multiple participants to securely compute the intersection of their private sets without the need for a trusted third party. First, each participant converts its private set into a binary vector form and exchanges random number sequences through a secure channel to generate random numbers that satisfy the constraint that the modulus sum is zero. The first participant is responsible for preparing multi-particle entangled states and applying a modular multiplication operation to specific particles to introduce random factors. Subsequently, the first participant distributes the entangled particles to each participant and inserts decoy particles for eavesdropping detection. After receiving the particles, each participant uses its random numbers and private data to perform phase rotation encoding on the corresponding particles. The encoded particle sequence is then sent to the last participant after eavesdropping detection. Finally, the last participant performs the inverse operation and global measurement on the received particles. By determining whether the measurement result equals the sum of the random factors of all participants, it determines which elements belong to the intersection and publishes the results for verification by all parties. This method fully utilizes the indistinguishability of quantum states and the concealment of phase encoding, effectively resisting attacks such as collusion attacks, intercept-retransmission, measurement-retransmission, and entangled measurement while ensuring correctness, thus possessing high security and feasibility.

[0009] The method described in this invention satisfies the following prerequisites:

[0010] (1) There are m mutually distrustful participants, denoted as m. ,in All participants collaboratively calculate the intersection of all sets;

[0011] (2) There exists a common set U, and each participant ( ) private collection All elements are selected from U;

[0012] (3) By the participating parties Generate entangled states and distribute particles to other participants, ultimately allowing the participants to... The received particles are measured to calculate the intersection result, and the participants... and As participants who supervise each other, collusion is not permitted;

[0013] Based on the above prerequisites, the method executes the following three stages:

[0014] (a) The steps in the initialization phase include:

[0015] S11, All Participating Parties Based on its own private collection Generate the corresponding vector The encoding rules are as follows:

[0016] ,

[0017] in, If the first [element] in the common set U... Each element belongs to ,Right now Then the element at the corresponding position in the vector ;like ,but This encoding transforms the "element ownership" problem of a private set into a "0-1 value selection" problem of a vector, providing a data foundation for subsequent quantum operations.

[0018] S12, Each participant Prepare n initial random number sequences, each sequence containing m random numbers, denoted as . ,in , corresponding to n common set elements; There are m participants; all random numbers must satisfy... Furthermore, the sum of random numbers within each sequence must satisfy a modulus of 0, i.e. . The t-th random number from each sequence is sent to the participants via a secure channel. ;at the same time, Receive corresponding random numbers sent by other participants to form a new random number sequence. .

[0019] S13, Each participant For the newly obtained random number sequence Summing by group generates a random number sequence. The sum of the j-th group is Since the initial sequence satisfies The sum of the j-th random numbers of all participants also satisfies This property provides a key basis for the subsequent verification of results.

[0020] S14, Participating Parties Generate n entangled states Each state is composed of It consists of d-level particles, and the preparation process is as follows:

[0021] First, prepare Single-particle state and for the initial particles Performing a QFT operation yields a quantum state. Subsequently, Control of particles The particle and the target particles are subjected to 2m XOR operations in sequence, eventually generating an entangled state. ;

[0022] S15, Participating Parties Generate a set of random numbers ,in And satisfy .in addition, For the nth entangled state Each particle executes Operation, i.e. At this point, the entangled state becomes:

[0023] .

[0024] S16, Participating Parties Arrange the n entangled states in order, and extract the nth entangled state from each entangled state. The and the first There are 10 particles, forming a sequence of m particles. ,in Participants Prepare Groups of decoy particles, each group of decoy particles randomly selected from the computational base or Fourier Select from the middle; randomly insert decoy particles into the sequence. , generate a new sequence ( ), and record the position of the decoy particles and the measurement baseline; participants Preserved sequences ,Will Send to the corresponding participants .

[0025] (ii) The steps in the execution phase include:

[0026] S21, Participating Parties Confirmation of sequence receipt Afterwards, the participating parties Announcement The location of the decoy particle and the corresponding measurement basis are determined. Based on the measurement results, both parties perform eavesdropping detection. If the error rate exceeds a preset limit, the agreement terminates; if the error rate meets the requirements, the participating parties... Remove decoy particles and restore the initial sequence. .

[0027] Participants For sequence Particles in and Execute operation and ,Right now , .

[0028] At this point, the entangled state transforms into:

[0029] .

[0030] S22, Each participant The processed sequence containing decoy particles is sent to the participants. ;at the same time, The random number set G and the first particle of the entangled state Send to ,Depend on All received particles are subjected to secondary eavesdropping detection.

[0031] (iii) The steps in the output stage include:

[0032] S31. After discarding the decoy particles Obtain all entangled states , .at the same time, For the first Each particle performs an operation. ,Right now .Then, Perform 2m XOR operations on the first particle (control particle) and the remaining 2m particles (target particles) to generate entangled states:

[0033] .

[0034] S32, Participating Parties Perform on entangled states ,get:

[0035] .

[0036] Subsequently, Measure all quantum states and record the measurement results. .like ,but The element is the intersection of the private sets of all participating parties.

[0037] S33, Participating Parties The intersection result of the private sets of all participants is published; other participants verify the correctness of the result based on their own private sets and random number sequences; if all participants confirm that the result is correct, then the result is the final intersection; if there is any objection, the protocol is re-executed.

[0038] Furthermore, the expression for the quantum Fourier transform (QFT) in the d-level quantum system is as follows: ,in , Inverse quantum Fourier transform ( The expression for ) is: ,in Let h represent the target qubit, and h represent the position of the target qubit.

[0039] The two sets of mutually unbiased bases of the d-level single-particle state are respectively computational bases. and Fourier , where F represents the quantum Fourier transform.

[0040] The revolving door (ROT) is designed for the following parameters. Defined as a phase operation: ,in Let h represent the target qubit, and h represent the position of the target qubit. The phase is related to the modulus-d operation of the quantum state amplitude.

[0041] Furthermore, the bitwise XOR gate is defined as follows: ,in This represents addition modulo d. , Indicates control of qubits, This represents the target qubit, while the control qubit remains unchanged. The target qubit performs a modular addition operation.

[0042] The Model-Use Gate (MUL) is for parameters Defined as: .

[0043] The specific methods for eavesdropping detection are as follows: (Participating parties) according to The published measurement standard measures the decoy particles, and the measurement results are compared with... The system compares the pre-set decoy particle state with the error rate; if the error rate exceeds the pre-set safety threshold, it is determined that eavesdropping has occurred and the protocol is terminated; if the error rate is within the safety threshold, it is determined that there is no eavesdropping and the subsequent steps are continued.

[0044] The method for performing eavesdropping detection during the execution phase is as follows: The published measurement standard measures the decoy particles in the receiving particles, compares the measurement results with the preset state, and determines whether there is eavesdropping based on the error rate, so as to ensure the security of quantum state transmission.

[0045] In the output phase S33, the verification results of other participants are processed as follows: Each participant... Based on one's own private collection Check Do all the published intersection elements belong to If all participants confirm that the intersection elements belong to their respective private sets, the intersection result is accepted; if any participant discovers that the intersection elements do not belong to their private sets, the protocol needs to be re-executed to obtain the correct intersection.

[0046] A medical data sharing system based on a phase-encoded, third-party-free quantum multi-party private set intersection protocol, wherein the method of the phase-encoded, third-party-free quantum multi-party private set intersection protocol achieves data encryption, and the medical data sharing system includes:

[0047] Quantum state generation module: deployed among participating parties Used to generate containing The entangled state of d-level particles is obtained, and a quantum Fourier transform and XOR operation are performed on the initial particle. At the same time, a random number set G is generated, and a modular multiplication operation is performed on the specific particles in the entangled state.

[0048] Sequence processing module: deployed to each participating party It is used to generate an encoded vector based on a private set, prepare an initial random sequence, exchange the sequence through a secure channel, and generate a summed random number sequence.

[0049] Quantum state transmission and eavesdropping detection module: used to transmit quantum sequences containing decoy particles between participants, and to detect eavesdropping behavior during transmission by comparing the measurement results of the decoy particles with the preset state;

[0050] Quantum manipulation module: deployed among various participating parties and Participants Perform a rotation operation on the received particles. Perform modular multiplication, XOR operation, and inverse quantum Fourier transform on the received particles;

[0051] Results Measurement and Verification Module: Deployed by participating parties Other participants, participants The intersection results are obtained by measuring the quantum states and published. Other participants verify the correctness of the results to ensure the accuracy of the intersection results.

[0052] Beneficial effects: It eliminates reliance on third parties, avoiding the risk of single points of failure and improving the security and reliability of the protocol; simultaneously, based on quantum state phase encoding and multiple quantum operations, the scheme only discloses elements of the intersection of sets, without revealing any other private set elements of any participating party, thus ensuring data privacy; furthermore, the scheme supports... In multi-participant scenarios, it has a wider range of applications than traditional two-party protocols, and can meet the needs of various collaborative scenarios such as anonymous authentication and vertical federated learning. Finally, through decoy particles and two eavesdropping detections, it can effectively resist attacks such as interception retransmission, measurement retransmission, and entanglement measurement, and has strong security. Attached Figure Description

[0053] Figure 1 This is the random number encoding method of the present invention;

[0054] Figure 2 This is a schematic diagram illustrating the encryption of private elements in this invention. Detailed Implementation

[0055] The quantum private set intersection protocol, combined with quantum technology, enables efficient acquisition of public elements of private sets while protecting the privacy of all parties. Existing solutions mostly target two-party scenarios or typically rely on a third party to achieve confidential intersection of private sets. However, in practical applications, establishing a trusted third party may introduce potential security risks. To address these issues, this implementation is based on a quantum intersection protocol that does not require a third party and is applicable to multiple participants. This protocol utilizes quantum state phase encoding technology to effectively compute the intersection of the private sets of each participant.

[0056] In this implementation, it is assumed that there are m mutually distrustful participants, denoted as mm. The intersection of the sets of all participating parties' collaborative computations, and a universal set U exists where each participating party... ( ) holds a private collection The elements in the set all come from the universal set U. During the protocol execution process, the participating parties... The responsible parties are responsible for preparing several entangled states and sending the corresponding particles to other participants, who will ultimately control them. The received particles are measured, and the intersection result is calculated. and As two parties who supervise each other, collusion is not permitted.

[0057] In practice, all participants first initialize their private sets, converting them into binary sets. Simultaneously, all clients generate keys by constructing matrices to enhance the protocol's security. Then, the participants... Several entangled states are prepared, and the corresponding particles are sent to other participants. To ensure the security of the particle transmission process, several decoy photons are inserted into the particle sequence. After the participants receive the particle sequence and complete the security check, they will perform different operations on the received particles according to their respective secret numbers. The processed particles are then sent to... ,Depend on The particles received from other participants are measured to obtain the intersection results.

[0058] The following details the implementation process of this agreement, including specific parameters and steps. Each participating party , , Complete series ,use Energy-level quantum system, all quantum operations are implemented based on the IBM Qiskit platform: I. Implementation Details of the Initialization Phase

[0059] (a) Private Vector Generation

[0060] Each participating party shall, in accordance with the "if" ( (corresponding to elements 0, 1, and 2 in the universal set U respectively), then the vector elements ;otherwise The rule of "" converts the private set into a binary vector. Among them, Private collections Generate vectors ; Private collections Generate vectors ; Private collections Generate vectors .

[0061] (II) Initial Random Sequence Preparation and Exchange

[0062] This stage is the foundational step in random number generation, starting with the preparation of an initial random sequence. Prepare 3 sets of initial sequences: , , And all sequences satisfy ; Prepare 3 sets of initial sequences: , , ; Prepare 3 sets of initial sequences: , , .

[0063] After initial sequence preparation is completed, cross-participant exchange is carried out. Send the second value of each group to The third value is sent ; Send the first value of each group to The third value is sent ; Send the first value of each group to The second value is sent After the exchange, Obtain a new sequence , , , Obtain a new sequence , , , Obtain a new sequence , , .

[0064] (III) Random Number Sequence Calculation

[0065] Each participant generates a random number sequence by summing the results of the swapped sequences. The calculation rule is as follows ( The specific calculation results are as follows: of ; of ; of And the j-th random number for all participants satisfies .

[0066] (iv) Preparation of entangled states

[0067] First, prepare 3 containing The entangled states of 1 particle (corresponding to the 3 elements of the universal set U) are first prepared with 7 initial single-particle states. ,right Perform a QFT operation to obtain ; then An XOR operation is performed with the remaining 6 target particles to generate an entangled state:

[0068] .

[0069] Subsequently, Generate random number sets ,satisfy For entangled states Particle execution , Particle execution , Particle execution The operation, the updated entangled state is: This involves hiding the private information carried by particles through modular multiplication operations.

[0070] (v) Decoy Particle Insertion and Particle Distribution

[0071] Participants Arrange the three entangled states in order and extract the first entangled state of each state. The and the first Each particle forms a sequence. To ensure the safety of particle transport, in and Decoy particles are randomly inserted into the mixture, and the decoy particles originate from mutually unbiased bases. or A new sequence is generated by randomly selecting and inserting a new sequence. and . Record the position of the decoy particles and the corresponding measurement base, Send to , Send to The particle distribution is completed.

[0072] II. Implementation Details of the Execution Phase

[0073] (a) Eavesdropping detection and sequence recovery

[0074] Participants , Received , back, The location and measurement basis of the decoy particles were published. , The decoy particles are measured according to the published information, and the error rate is calculated. In this embodiment, if the error rate is lower than the threshold, it is confirmed that there is no eavesdropping and the protocol continues to be executed; if the error rate exceeds the threshold, the protocol is terminated immediately and the process is restarted.

[0075] , Remove decoy particles from the sequence and restore the initial sequence. , Each participant uses its own random number sequence. With binary vectors Perform the ROT operation on the particles in the sequence: right implement ,right implement ; right implement ,right implement ; right implement ,right implement .

[0076] (ii) Returning Particles

[0077] , The processed sequence containing decoy particles is sent to the participants. ;at the same time, The random number set G and the first particle of the entangled state Send to ,Depend on All received particles are subjected to secondary eavesdropping detection.

[0078] III. Implementation Details of the Output Phase

[0079] (I) Decryption and Processing of Entangled States

[0080] After discarding the decoy particles Obtain all entangled states , .at the same time, For the first Each particle performs an operation. ,Right now .Then, Perform an XOR operation on the first particle (the control particle) and the remaining 6 particles to obtain a simplified entangled state:

[0081] .

[0082] (II) Measurement and Intersection Determination

[0083] For the 3 simplified Execute separately And measurements were taken to obtain the results. According to the protocol logic, only when hour, ,at this time In this embodiment, ,correspond Therefore, 1 is the intersection element of the private sets of all participants.

[0084] (III) Result Verification and Confirmation

[0085] Announcement of preliminary intersection set ; , The result was verified individually, confirming that 1 belongs to each party's private set, with no objections. Finally, the intersection of all participating parties' private sets was determined to be... The agreement has been executed.

[0086] Application instructions:

[0087] This invention presents a secure computing scheme based on quantum state phase encoding, enabling multiple participants to securely compute the intersection of their private data without third-party intervention, while ensuring the privacy of non-intersection elements is not compromised. This technology has significant application value in scenarios requiring cross-institutional collaborative processing of sensitive data, particularly excelling in the collaborative diagnosis of rare diseases across multiple hospitals.

[0088] Taking spinal muscular atrophy (SMA) as an example, a diagnosis of this disease requires three key data points simultaneously: a positive pathogenic gene test, typical clinical symptoms, and a family history of the disease. However, this data is often scattered across different medical institutions. For instance, the genetics department of a tertiary hospital may hold a "patient identifier set of pathogenic genes" confirmed by genetic testing, the neurology department of a children's hospital holds a "patient identifier set of typical symptoms" based on clinical testing, and a maternal and child health hospital has a "patient identifier set of genetic history" from family health records. Due to the sensitivity of medical data and the lack of mutual trust between institutions, traditional methods of information sharing, such as patients transmitting information themselves or hospitals directly sharing data, not only make it difficult to guarantee the integrity of the information—patients cannot accurately describe professional genetic results, quantify symptoms, or provide a complete family medical history—but also pose serious privacy and compliance risks. For example, direct sharing may lead to the leakage of information from patients outside the hospital's network, while relying on third-party platforms faces problems such as data tampering or single points of failure.

[0089] This invention utilizes quantum state phase encoding technology to enable all parties to accurately identify patients who simultaneously meet all diagnostic criteria in an encrypted state, without exchanging original data. The entire process does not rely on a third-party platform, protecting the proprietary data of each hospital from leakage and complying with medical information security standards, thus providing a safe and reliable technical path for cross-institutional collaborative diagnosis.

Claims

1. A method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding, characterized in that, The protocol does not rely on a third party and uses quantum state phase encoding to achieve private set intersection calculation of multiple participants, thus protecting the privacy of non-intersection elements of each participant. The method satisfies the following prerequisites: (1) m mutually distrustful participants are denoted as All participants collaboratively calculate the intersection of all sets; (2) Construct a common set U, for each participant Private collection All elements are selected from the common set U; (3) By the participating parties Generate entangled states and distribute particles to other participants, ultimately allowing the participants to... The received particles are measured to calculate the intersection result, and the participants... and As participants who supervise each other, collusion is not permitted; Based on the above prerequisites, the method executes the following three stages: (I) Initialization Phase All participating parties According to private collection Generate vectors Each element The encoding method is as follows: in, ; Participants Prepare n initial sequences ,in , , And satisfy Participants The t-th value of each sequence is sent to the participants via a secure channel. Simultaneously, it receives sequences from other participants to obtain a new sequence. ; Participants For the new sequence Summing the elements in the array generates a random number sequence. ,in , And the j-th random number of all participants satisfies Where mod represents the modulo operation; Participants Generate n entangled states Each state is composed of Composed of d-level particles, any entangled state The construction process is as follows: First, prepare Single-particle state For the initial particle Performing a quantum Fourier transform operation yields... QFT stands for Fourier Transform; subsequently, the participants... Perform 2m XOR operations on the first particle and the remaining 2m particles to generate entangled states: ; Participants Generate a set of random numbers ,in And it is required to meet the following conditions. Participants For each entangled state, the first Each particle performs an operation. , At this point, the entangled state becomes: ； Participants Arrange the n entangled states in order, and extract the nth entangled state from each entangled state. The and the first 10 particles, forming m sequences ,in: ； First, prepare A set of decoy particles, each decoy particle randomly selected from the base set. or Select from the sequence and randomly insert it into the sequence. , generate a new sequence Record the position and measurement basis of the decoy particles, then Preserved sequences ,Will Send to the corresponding participants ; (II) Implementation Phase Participants Confirmation of sequence receipt back, Announcement The location of the decoy particle and the corresponding measurement basis are determined. Based on the measurement results, both parties perform eavesdropping detection: if the error rate exceeds a preset limit, the agreement terminates; if the error rate meets the requirements, ... Remove decoy particles and restore the initial sequence. ; Participants For sequence Particles in and Execute operation and ,Right now , At this point, the entangled state transforms into... ； Participants Send all particles along with the decoy state to ,at the same time The random number G and the first particle of the entangled state Send to To conduct eavesdropping detection, participating parties Perform eavesdropping checks on all received particles; (III) Output Stage Participants After discarding the decoy particles, all entangled states are obtained. , and for the first Each particle performs an operation. ,Right now Subsequently Perform 2m XOR operations on the first particle and the remaining 2m particles to generate entangled states: Participants Perform inverse quantum Fourier transform on entangled states ,Right now: ， Subsequently Measure all quantum states and store the results. ,like ,but The intersection of the private sets of all participants; Participants The intersection set of all participants is published, and the other participants verify the result. If all participants agree, the result is the correct representation of the intersection set.

2. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The expression for the quantum Fourier transform in the d-level quantum system is: ,in , The expression for the inverse quantum Fourier transform is: ,in Let h represent the target qubit, and h represent the position of the target qubit.

3. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The two sets of mutually unbiased bases of the d-level single-particle state are respectively computational bases. and Fourier , where F represents the quantum Fourier transform operation.

4. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The revolving door is for parameters Defined as a phase operation: ,in Let h represent the target qubit, and h represent the position of the target qubit. The phase is related to the modulus d operation of the quantum state amplitude, and ROT represents the rotation operation.

5. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The bitwise XOR operation is defined as follows: ,in This represents addition modulo d. , Indicates control of qubits, The target qubit is defined as the control qubit, which remains unchanged. The target qubit performs a modular addition operation, and XOR represents the exclusive OR operation.

6. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The modular multiplication gate is for parameters Defined as: MUL stands for modular multiplication.

7. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The specific methods for detecting eavesdropping are as follows: Participants according to The published measurement standard measures the decoy particles, and the measurement results are compared with... The system compares the pre-set decoy particle state with the error rate; if the error rate exceeds the pre-set safety threshold, it is determined that eavesdropping has occurred and the protocol is terminated; if the error rate is within the safety threshold, it is determined that there is no eavesdropping and the subsequent steps are continued.

8. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, During the execution phase, the participating parties The method for conducting eavesdropping detection is: according to the participating parties The published measurement standard measures the decoy particles in the receiving particles, compares the measurement results with the preset state, and determines whether there is eavesdropping based on the error rate, so as to ensure the security of quantum state transmission.

9. The method for finding intersections of quantum multi-party privacy sets without third parties based on phase encoding according to claim 1, characterized in that, The method for other participants to verify the results during the output phase is as follows: All participating parties Based on one's own private collection Check Do all the published intersection elements belong to If all participants confirm that the elements in the intersection belong to their respective private sets, then the intersection result is accepted. If any participant discovers that an element in the intersection does not belong to its private set, the protocol must be re-executed to obtain the correct intersection.

10. A medical data sharing system based on a phase-encoded, third-party-free quantum multi-party private set intersection protocol, characterized in that, The phase-encoded, third-party-free quantum multi-party privacy set intersection protocol, according to any one of claims 1-9, implements encryption during data sharing. The medical data sharing system includes the following modules: Quantum state generation module: deployed among participating parties Used to generate containing The entangled state of d-level particles is obtained, and a quantum Fourier transform and XOR operation are performed on the initial particle. At the same time, a random number set G is generated, and a modular multiplication operation is performed on the specific particles in the entangled state. Sequence processing module: deployed to each participating party It is used to generate an encoded vector based on a private set, prepare an initial random sequence, exchange the sequence through a secure channel, and generate a summed random number sequence. Quantum state transmission and eavesdropping detection module: used to transmit quantum sequences containing decoy particles between participants, and to detect eavesdropping behavior during transmission by comparing the measurement results of the decoy particles with the preset state; Quantum manipulation module: deployed among various participating parties and Participants Perform a rotation operation on the received particles. Perform modular multiplication, XOR operation, and inverse quantum Fourier transform on the received particles; Results Measurement and Verification Module: Deployed by participating parties And other participating parties, The intersection results are obtained by measuring the quantum states and published. Other participants verify the correctness of the results to ensure the accuracy of the intersection results.

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