Quantum state protocol construction system
Through the quantum state information interaction between Alice and Bob, secure multi-party secure computing is achieved using existing quantum communication devices, which solves the security and applicability issues of existing protocols, reduces the risk of eavesdropping, and expands the scope of application of the protocol.
Patent Information
- Application Number
- CN202511123714.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-10-14
AI Technical Summary
The security of existing multi-party secure computing protocols is threatened in quantum computing environments. They require the participation of a semi-honest third party and are difficult to prepare and measure multiple entangled quantum bits, which limits the scope of application and privacy security of the protocols.
Alice and Bob use quantum state information-based interaction and existing quantum communication devices to encode, process and measure optical pulses, avoiding the preparation and measurement of entangled states, enabling comparison of digital sizes and reducing the risk of eavesdropping.
It realizes the comparison of the size of numbers of both parties without leaking privacy information, reduces the risk of privacy information leakage, expands the scope of application of the protocol, and avoids dependence on high-dimensional entangled quantum measurement devices.
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Figure CN120785536A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application provides a quantum state protocol construction system and relates to the technical field of quantum communication. BACKGROUND
[0002] Multi-party secure computation protocols have a wide application prospect in the fields of financial services, data analysis, security evaluation, etc. However, the security of the existing multi-party secure computation protocols is based on the algorithm using congruence and prime factor decomposition. With the development of quantum computing, the security of the algorithm based on prime factor decomposition and other algorithms based on computational complexity is threatened, thereby affecting the privacy security of the protocol participants.
[0003] The quantum multi-party secure computation protocol based on quantum state encoding information can make up for the quantum computing vulnerability in the existing protocol algorithm. However, the existing quantum multi-party secure computation protocol, such as the quantum millionaire protocol, needs to add a semi-honest third party, which will limit the application scope of the protocol. In addition, the existing quantum multi-party computation protocol needs to prepare multiple entangled states of quantum bits, and needs to perform joint operation and joint measurement on the entangled state, so it is difficult to realize the preparation and measurement of multiple entangled quantum bits using the existing common devices of quantum communication. SUMMARY
[0004] The application provides a multi-party computation protocol and system based on quantum states, with two participants Alice and Bob. Through the interaction between the two protocol participants based on quantum state information, the size of the private numbers held by Alice and Bob can be compared, while avoiding the leakage of the number privacy to the other party or a third party. In addition, the Alice end and the Bob end of the system are based on the common devices of existing quantum communication, and do not involve the preparation and measurement of entangled states, thereby increasing the practicability of the quantum multi-party secure computation protocol.
[0005] A quantum state protocol construction system, comprising: an Alice end, a Bob end and an optical fiber link; the Alice end modulates optical pulses into quantum optical pulses carrying two mutually orthogonal polarization states, and sends the quantum optical pulses to the Bob end via the optical fiber link;
[0006] The Bob end receives the quantum optical pulses sent by the Alice end, extracts one optical pulse, and scrambles the time sequence of the remaining optical pulses, and then returns the optical pulses to the Alice end via the optical fiber link;
[0007] The Alice end measures the quantum state information of the optical pulses by detecting the returned optical pulses, and determines the type of the optical pulse extracted by the Bob end.
[0008] In a preferred embodiment, the Alice end includes: a light source, an encoding module, an output module, an input module, a measurement module, and a control module; the light source generates light pulses for encoding quantum state information; the encoding module modulates the light pulses into quantum light pulses carrying two mutually orthogonal polarization states; the output module sends the quantum light pulses to the Bob end via an optical fiber link; the input module receives the light pulses returned from the Bob end from the optical fiber link and transmits them to the measurement module; the measurement module measures the quantum state information of the light pulses by detecting the light pulses; the control module controls the encoding module and the measurement module, and converts the detection results of the measurement module into classical information;
[0009] In a preferred embodiment, the Bob end includes: an input module, a processing module and an output module; the input module receives the optical pulse sent by Alice in the optical fiber link and sends it to the processing module; the processing module extracts the specified optical pulse and disrupts the time sequence of the remaining optical pulses; the output module sends the remaining optical pulses back to Alice's end through the optical fiber link.
[0010] In a preferred embodiment, the encoding module includes: a phase modulator, an intensity modulator, a polarization modulator, and a variable optical attenuator;
[0011] The light pulse emitted by the light source is modulated in intensity and phase by the phase modulator and intensity modulator, and then encoded into the horizontal polarization state |H> or the vertical polarization state |V> by the polarization modulator:
[0012] Among them, the horizontal polarization state vertical polarization state
[0013] Where |0> and |1> are standard orthogonal polarization states, The phase value set for Alice's end;
[0014] The variable optical attenuator attenuates the intensity of light pulses.
[0015] In a preferred embodiment, the measurement module comprises: a polarization modulator, a beam splitter, and a single photon detector;
[0016] The polarization modulator performs polarization modulation on the received optical pulse, compensates for the polarization change caused by the link, so that the horizontal polarization state |H> light is consistent with the horizontal polarization state |H> light emitted from the horizontal end of the beam splitter, and the vertical polarization state |V> light is consistent with the vertical polarization state |V> light emitted from the vertical end of the beam splitter; the beam splitter splits the light based on the polarization state of the optical pulse, and the single-photon detector is located at the horizontal end of the beam splitter; the beam splitter and the single-photon detector convert the quantum state information carried by the optical pulse into classical information by measuring the polarization state of the optical pulse, wherein all the horizontal polarization state |H> light enters the horizontal end of the beam splitter, and the single-photon detector counts; all the vertical polarization state |V> light enters the vertical end of the beam splitter, and the beam splitter does not count.
[0017] In the preferred embodiment, the number held by Alice is a, the number held by Bob is b, and Alice and Bob perform a quantum secure multi-party computation protocol by the following process to compare the size of a and b:
[0018] Alice side performs quantum state information polarization encoding on n optical pulses, so that the horizontal polarization state |H> light can all enter the single-photon detector, and the vertical polarization state |V> light enters the vertical end of the beam splitter, the first a optical pulses are polarization modulated as horizontal polarization state |H>, and the last n-a optical pulses are polarization modulated as vertical polarization state |V>;
[0019] Bob receives n optical pulses, discards the b+1th optical pulse through the processing module, and then sends the remaining optical pulses to Alice in random order; the n-1 optical pulses returned to Alice are sequentially input into the measurement module for measurement, and the response frequency of the single-photon detector is recorded;
[0020] If the response frequency of the single-photon detector is a-1, it means that the b+1th pulse polarization encoded by Bob is horizontal polarization state |H>, and the result b
[0021] In the preferred embodiment, before performing the quantum secure multi-party computation protocol, a reference optical pulse is sent, and the intensity of the reference optical pulse is higher than that of the encoded pulse; based on the detection result of the reference optical pulse, the polarization modulator of the measurement module is adjusted to compensate for the polarization change in the link.
[0022] In the preferred embodiment, during the execution of the protocol, the two parties executing the protocol prepare decoy state optical pulses based on the shared key of the QKD protocol, the phase and intensity of the decoy state pulse are different from those of the signal pulse, and by measuring the decoy state optical pulse, it is determined whether there is a potential eavesdropper in the link.
[0023] In the preferred embodiment, the processing module comprises an input interface, a first switcher, a second switcher, m links with different lengths and an output interface; the first port of the first switcher is connected to the second switcher, and the second port is used for discarding optical pulses; the second switcher is controlled by a random number signal, so that the input optical pulses enter one of the m links, one end of each link is connected to the second switcher, and the other end is connected to the output interface.
[0024] In the preferred embodiment, the process that Bob takes away the b+1th encoding pulse and then sends the remaining encoding pulses to Alice in disorder is as follows: Bob inputs the n optical pulses received by the input module from the input interface in sequence, if the current time window is not the time window of the b+1th optical pulse, the first switcher switches to the first port output, and the second switcher is controlled by a random number signal, so that the optical pulses enter one of the m links with different lengths, and the optical pulses passing through the link enter the output interface and are sent to Alice, if the current time window is the time window of the b+1th optical pulse, the first switcher switches to the second port output, and the b+1th optical pulse enters port 2 and is discarded.
[0025] Compared with the prior art, the present application has the following beneficial technical effects:
[0026] 1. The execution mode of the quantum multi-party secure computing protocol can compare two numbers without knowing the specific numbers of the other party by encoding, processing and measuring quantum state information.
[0027] 2. The device setting based on the quantum multi-party secure computing protocol can prepare, process and measure quantum state information, execute the protocol based on quantum state information, and reduce the risk of eavesdropping.
[0028] 3. The protocol has two participants Alice and Bob, and does not need a third party as a verification party, thereby reducing the risk of privacy information leakage.
[0029] 4. The quantum multi-party secure computing protocol device setting based on commonly used devices in quantum communication avoids using immature quantum-related equipment such as quantum storage and high-dimensional entangled quantum measurement devices, thereby increasing the application range of the protocol. BRIEF DESCRIPTION OF DRAWINGS
[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0031] Figure 1A schematic diagram of the composition of the Alice end;
[0032] Figure 2 A schematic diagram of the encoding module;
[0033] Figure 3 A schematic diagram of the measurement module;
[0034] Figure 4 A schematic diagram of the composition of the Bob end;
[0035] Figure 5 A quantum multi-party secure computing process embodiment;
[0036] Figure 6 A schematic diagram of the processing module;
[0037] Figure 7 A coding pulse feedback flowchart. DETAILED DESCRIPTION
[0038] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0039] In the drawings of the specific embodiments of the present application, in order to better and more clearly describe the working principles of the elements in the system and the connection relationship of the parts in the device, only the relative position relationship between the elements is distinguished, and the signal transmission direction, connection order and the size and shape of the parts in the structure cannot be limited.
[0040] Secondly, the "one embodiment" or "embodiment" referred to herein means that a specific feature, structure or characteristic can be included in at least one implementation of the present application. The "in one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is separate or alternative to other embodiments.
[0041] The present application proposes a quantum multi-party secure computing protocol construction system, comprising: an Alice end, a Bob end and an optical fiber link. As shown in the figure, the Alice end comprises: a light source, an encoding module, an output module, an input module, a measurement module and a control module. Figure 1
[0042] The light source can generate light pulses for encoding quantum state information; in a preferred embodiment, the light source uses a narrow-band laser.
[0043] The encoding module can modulate the intensity, polarization, phase and other characteristics of the optical pulse, and modulate the optical pulse into a quantum optical pulse carrying two mutually orthogonal polarization states.
[0044] Encoding module such as Figure 2 As shown, it includes: phase modulator PM, intensity modulator IM, polarization modulator PolM, and variable optical attenuator ATT. After the light pulse emitted by the light source is modulated in intensity and phase by the phase modulator and intensity modulator, the polarization modulator encodes the light pulse into one of two polarization states:
[0045] Horizontal polarization state and vertical polarization state
[0046] Where |0> and |1> are standard orthogonal polarization states, The phase value set by Alice is kept secret from others. ATT can attenuate the intensity of the optical pulse and transmit it to the output module.
[0047] The output module can send the encoded quantum light pulse to Bob via the optical fiber link;
[0048] The input module can receive the optical pulses returned from the Bob end of the optical fiber link and transmit them to the measurement module;
[0049] The measurement module can measure quantum state information by detecting light pulses.
[0050] Quantum state measurement module such as Figure 3 As shown, the system comprises a polarization modulator (PolM), a beam splitter (PBS), and a single-photon detector (SPD). The PolM performs polarization modulation on received optical pulses to compensate for polarization changes caused by the link. This ensures that light with a horizontal polarization state (|H>) matches the light with a horizontal polarization state (|H>) emitted from the horizontal end of the PBS, while light with a vertical polarization state (|V>) matches the light with a vertical polarization state (|V>) emitted from the vertical end of the PBS. The beam splitter (PBS) splits the optical pulses based on their polarization states, and the single-photon detector (SPD) is located at the horizontal end of the beam splitter. The beam splitter (PBS) and the single-photon detector (SPD) convert the quantum state information carried by the optical pulses into classical information by measuring their polarization states. When all light with a |H> state enters the horizontal end of the beam splitter (PBS), the single-photon detector (SPD) counts; when all light with a vertical polarization state (|V>) enters the vertical end of the beam splitter (PBS), the single-photon detector (SPD) does not count.
[0051] The control module can control the encoding and measurement of quantum states, generate and store classical information, and convert the detection results of the quantum state measurement module into classical information.
[0052] Bob Duanru Figure 4As shown, Bob's end includes: an input module, a processing module and an output module.
[0053] The input module can receive the optical pulses sent by Alice in the optical fiber link and send them to the processing module; the processing module can extract a specific optical pulse and disrupt the time sequence of the remaining optical pulses; the output module can send the remaining optical pulses back to Alice through the optical fiber link.
[0054] Figure 5 The following are the specific steps for using quantum state protocols to build a system to execute quantum multi-party secure computing protocols:
[0055] The two parties to the agreement are Alice and Bob, where Alice holds the number a and Bob holds the number b, both of which are integers less than n. Alice and Bob execute the quantum secure multi-party computing protocol through the following process to compare the sizes of a and b.
[0056] (1) Quantum state encoding of light pulses.
[0057] Alice encodes the quantum state information polarization of n light pulses and sets the phase Adjust the polarization modulator PolM in the quantum state measurement module so that all light with the horizontal polarization state |H> enters the single-photon detector, while light with the vertical polarization state |V> enters the vertical end of the PBS. The polarization of the first a light pulses is modulated to the horizontal polarization state |H>, and the polarization of the next na light pulses is modulated to the vertical polarization state |V>.
[0058] (2) Send coded pulses
[0059] Alice sends these n light pulses to Bob in sequence through the quantum channel.
[0060] (3) Encoded pulse feedback
[0061] Bob receives these n light pulses, discards the b+1th light pulse through the processing module, and then sends the remaining light pulses to Alice in a random order.
[0062] (4): Measure quantum state information. The n-1 light pulses returned to Alice are sequentially input into the quantum state measurement module for measurement, and the number of responses of the single-photon detector is recorded.
[0063] (5): Analysis of measurement results. If the number of responses of the single-photon detector is a-1, it means that the polarization code of the b+1th pulse taken by Bob is the horizontal polarization state |H>, and the result is recorded as b <a;
[0064] If the number of responses of the single-photon detector is a, it means that the polarization code of the b+1th pulse taken by Bob is the vertical polarization state |V>, and the result is recorded as b≥a;
[0065] If the measurement result is other, the protocol is terminated and an error is reported.
[0066] Optionally, before executing the protocol, a reference light pulse can be sent, which has a higher intensity than the encoding pulse. Based on the detection result of the reference light pulse, the PolM of the quantum state measurement module is adjusted to compensate for the polarization variation in the link.
[0067] In a preferred embodiment, the structure of the processing module is as follows Figure 6 As shown, the system includes an input interface, a first switch 1, a second switch 2, links 1, 2, ..., and m of varying lengths, and an output interface. First port 1 of first switch 1 is connected to second switch 2, and second port 2 is used to discard optical pulses. Second switch 2 is controlled by a random number signal to direct input optical pulses to one of links 1, 2, ..., and m. Links 1, 2, ..., and m of varying lengths are each connected at one end to second switch 2 and at the output interface at the other end.
[0068] like Figure 7 As shown, in the quantum multi-party secure computing protocol process, Bob takes the b+1th coded pulse and then sends the remaining coded pulses to Alice in a shuffled order. The process is as follows: Bob inputs the n optical pulses received by the input module into the input interface in turn. If the current time window is not the time window of the b+1th optical pulse, the first switch 1 switches to the first port 1 output, and the second switch 2 is controlled by a random number signal to make the optical pulse enter one of the m links of unequal lengths. The optical pulse passing through the link enters the output interface and is sent to Alice. If the current time window is the time window of the b+1th optical pulse, the first switch 1 switches to the second port 2 output, and the b+1th optical pulse enters the second port 2 and is discarded.
[0069] Optionally, during the protocol execution, both parties can generate decoy optical pulses based on the QKD protocol's shared key. These pulses have properties such as phase and intensity that differ from the signal pulses. By measuring these decoy optical pulses, the presence of potential eavesdroppers on the link can be determined.
[0070] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.
[0071] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0072] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.
Claims
1. A quantum state protocol construction system, characterized in that: include: Alice end, Bob end and optical fiber link; Alice end modulates the optical pulse into a quantum optical pulse carrying two mutually orthogonal polarization states, and sends it to Bob end via the optical fiber link; Bob receives the quantum light pulse sent by Alice, extracts one light pulse, and shuffles the time sequence of the remaining light pulses, and then returns them to Alice via the optical fiber link; The Alice end measures the quantum state information of the light pulse by detecting the returned light pulse, and determines the type of the light pulse extracted by the Bob end.
2. The quantum state protocol construction system according to claim 1, characterized in that: The Alice end includes: a light source, an encoding module, an output module, an input module, a measurement module and a control module; the light source generates light pulses for encoding quantum state information; the encoding module modulates the light pulses into quantum light pulses carrying two mutually orthogonal polarization states; the output module sends the quantum light pulses to the Bob end via an optical fiber link; the input module receives the light pulses returned from the Bob end from the optical fiber link and transmits them to the measurement module; the measurement module measures the quantum state information of the light pulses by detecting the light pulses; the control module controls the encoding module and the measurement module, and converts the detection results of the measurement module into classical information.
3. The quantum state protocol construction system according to claim 2, characterized in that: The Bob end includes: an input module, a processing module and an output module; the input module receives the optical pulse sent by Alice in the optical fiber link and sends it to the processing module; the processing module extracts the specified optical pulse and disrupts the time sequence of the remaining optical pulses; the output module sends the remaining optical pulses back to Alice's end through the optical fiber link.
4. The quantum state protocol construction system according to claim 3, characterized in that: The encoding module includes: phase modulator, intensity modulator, polarization modulator, and variable optical attenuator; The light pulse emitted by the light source is modulated in intensity and phase by the phase modulator and intensity modulator, and then encoded into the horizontal polarization state |H> or the vertical polarization state |V> by the polarization modulator: Among them, the horizontal polarization state vertical polarization state Where |0> and |1> are standard orthogonal polarization states, The phase value set for Alice's end; The variable optical attenuator attenuates the intensity of light pulses.
5. The quantum state protocol construction system according to claim 4, characterized in that: The measurement module includes: polarization modulator, beam splitter and single photon detector; The polarization modulator performs polarization modulation on the received optical pulse to compensate for the polarization change caused by the link, so that the horizontal polarization state |H> light is consistent with the horizontal polarization state |H> light emitted from the horizontal end of the beam splitter, and the vertical polarization state |V> light is consistent with the vertical polarization state |V> light emitted from the vertical end of the beam splitter; the beam splitter splits the light pulse based on the polarization state, and the single-photon detector is located at the horizontal end of the beam splitter; the beam splitter and the single-photon detector convert the quantum state information carried by the light pulse into classical information by measuring the polarization state of the light pulse, where the horizontal polarization state |H> light all enters the horizontal end of the beam splitter, and the single-photon detector counts; the vertical polarization state |V> light all enters the vertical end of the beam splitter, and the beam splitter does not count.
6. The quantum state protocol construction system according to claim 5, characterized in that: Alice holds a number, and Bob holds b. Alice and Bob perform a quantum secure multi-party computation protocol to compare the values of a and b using the following process: The Alice side performs polarization encoding of quantum state information on n optical pulses, such that all the light with horizontal polarization state |H> can enter the single-photon detector, while the light with vertical polarization state |V> enters the vertical end of the beam splitter. The first a optical pulses are polarization-modulated into the horizontal polarization state |H>, and the subsequent n - a optical pulses are polarization-modulated into the vertical polarization state |V>. The Bob side receives n optical pulses, discards the (b + 1)-th optical pulse through the processing module, and then sends the remaining optical pulses to the Alice side after scrambling the order; the n - 1 optical pulses returned to the Alice side are sequentially input into the measurement module for measurement, and the response times of the single-photon detector are recorded. If the response times of the single-photon detector is a - 1, it indicates that the polarization encoding of the (b + 1)-th pulse taken away by Bob is the horizontal polarization state |H>, and the recorded result is b < a; if the response times of the single-photon detector is a, it indicates that the polarization encoding of the (b + 1)-th pulse taken away by Bob is the vertical polarization state |V>, and the recorded result is b ≥ a; if the measurement result is otherwise, the protocol is terminated and an error is reported back.
7. The quantum state protocol construction system according to claim 6, characterized in that: Before executing the quantum secure multi-party computation protocol, reference optical pulses are sent, and the intensity of the reference optical pulses is higher than that of the encoded pulses. Based on the detection results of the reference optical pulses, the polarization modulator of the measurement module is adjusted to compensate for the polarization changes in the link.
8. The quantum state protocol construction system according to claim 6, characterized in that: During the execution of the protocol, both parties executing the protocol prepare decoy-state optical pulses based on the shared key of the QKD protocol. The phases and intensities of the decoy-state pulses are different from those of the signal pulses. By measuring the decoy-state optical pulses, it is determined whether there are potential eavesdroppers in the link.
9. The quantum state protocol construction system according to claim 3, characterized in that: The processing module includes an input interface, a first switch, a second switch, m links with different lengths, and an output interface; the first port of the first switch is connected to the second switch, and the second port is used to discard optical pulses; the second switch is controlled by a random number signal to allow the input optical pulses to enter one of the m links, and one end of each link is connected to the second switch, and the other end is connected to the output interface.
10. The quantum state protocol construction system according to claim 6, characterized in that: The process by which the Bob side takes away the (b + 1)-th encoded pulse and then sends the remaining encoded pulses to the Alice side after scrambling the order is as follows: Bob sequentially inputs the n optical pulses received by the input module through the input interface. If the current time window is not the time window of the (b + 1)-th optical pulse, the first switch switches to the first port for output, and the second switch is controlled by a random number signal to allow the optical pulse to enter one of the m links with different lengths. The optical pulse passing through the link enters the output interface and is sent to Alice. If the current time window is the time window of the (b + 1)-th optical pulse, the first switch switches to the second port for output, and the (b + 1)-th optical pulse enters port 2 and is discarded.