CN116232455B - Immune channel disturbance measurement equipment irrelevant quantum key distribution system - Google Patents
Immune channel disturbance measurement equipment irrelevant quantum key distribution system Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
- H04B10/0795—Performance monitoring; Measurement of transmission parameters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0819—Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s)
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0852—Quantum cryptography
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Abstract
The invention belongs to the technical field of secret communication, and discloses a measuring equipment independent quantum key distribution system for immune channel disturbance, which comprises two transmitters and a measuring party; the two transmitters are respectively connected with the measuring party through corresponding optical fiber channels; the measuring party comprises a first polarization path selection module, a second polarization path selection module, a beam splitter, a first single photon detector and a second single photon detector. Compared with the prior art, the polarization splitting module is added on the sender, the polarization splitting is carried out on the measuring party, and the orthogonal polarization component bidirectional multiplexing beam splitter is used for interference and then polarization beam combination is carried out, so that the influence of the polarization disturbance of the immunity channel of the Bell state measuring result can be greatly improved, and the stability of the system is greatly improved; active polarization compensation is not needed, and only two single photon detectors are needed, so that the complexity and cost of the system are reduced.
Description
Technical Field
The invention relates to the technical field of secret communication, in particular to a measurement equipment independent quantum key distribution system for immune channel disturbance.
Background
Quantum key distribution can provide information theory security for both communication parties, but due to the non-perfection of actual devices, security vulnerabilities exist in the system, wherein the most common vulnerabilities are found in the aspect of measuring equipment. The proposal of a measurement device independent quantum key distribution protocol (MDI-QKD) removes the trusted requirement on a measurement end, can immunize all attacks aiming at the measurement end, and greatly improves the actual security of the system.
MDI-QKD requires a communication two-way untrusted third party to send the quantum state for bell state measurement, while stable bell state measurement requires that the incident two states be polarized identically. Because the quantum states sent by the two sending ends are transmitted to the measuring end through different optical fiber channels, the polarization state of photons changes randomly along with the environment in the propagation process due to the double refraction effect of the optical fibers, so that the polarization states of photons are inconsistent when the photons reach a third party to perform Bell state measurement, and the measurement result is influenced. The conventional solution is to calibrate the polarization reference system in real time by using an active polarization compensation module, in the literature Tang, y.l., et al, "Measurement-device-independent quantum key distribution over, 200, km," Phys.rev. Lett. 113, 190501 (2014), and the literature Liu, h., et al, "Experimental demonstration of high-rate Measurement-device-independent quantum key distribution over asymmetric channels," Phys. Rev. Lett, 122,160501 (2018), where after each optical signal is polarized and split by using one polarization beam splitter at the Measurement end, one of the split components is detected as a feedback control signal of the polarization controller to calibrate the polarization reference system in real time, thus requiring two additional single photon detectors, increasing the cost and complexity of the system. Literature Wang, c., et al, "Measurement-device-independent quantum key distribution robust against environmental disturbs," optics, 4 (9): 1016-1023 (2017) & patent CN107332627B propose a solution that adds cost and complexity to the system by performing real-time disturbing on the quantum states at the transmitting end and polarization splitting at the third party measuring end, and separately measuring each polarization component with a set of bell state measuring devices, requiring 2 beam splitters and 4 single photon detectors.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a measuring equipment independent quantum key distribution system for immune channel disturbance.
The technical scheme of the invention is realized as follows:
a measuring equipment independent quantum key distribution system for immune channel disturbance comprises a first sender, a second sender and a measuring party; the first sender and the second sender are respectively connected with the measuring party through a first optical fiber channel and a second optical fiber channel;
the first sender and the second sender both comprise a quantum state preparation module and a depolarization module DEP;
the quantum state preparation module is used for generating a quantum state of time phase coding;
the depolarization module DEP is used for reducing the polarization degree of the quantum state to be close to 0 and outputting the polarization degree to a fiber channel;
the measuring party comprises a first polarization path selection module PPSM1, a second polarization path selection module PPSM2, a beam splitter BS, a first single photon detector SPD1 and a second single photon detector SPD2; the first port of the first polarization path selection module PPSM1 and the first port of the second polarization path selection module PPSM2 are respectively used as two input ports of a measuring party; the second port of the first polarization path selection module PPSM1 is correspondingly connected with the first port and the fourth port of the beam splitter BS respectively through a first polarization maintaining optical fiber and the second port of the second polarization path selection module PPSM2 through a second polarization maintaining optical fiber; the third port of the first polarization path selection module PPSM1 is correspondingly connected with the second port and the third port of the beam splitter BS respectively through a third polarization maintaining optical fiber and the third port of the second polarization path selection module PPSM2 through a fourth polarization maintaining optical fiber; the fourth port of the first polarization path selection module PPSM1 and the fourth port of the second polarization path selection module PPSM2 are respectively correspondingly connected with the first single photon detector SPD1 and the second single photon detector SPD2;
the first polarization path selection module PPSM1 is configured to perform polarization beam splitting on a quantum state input to a first port thereof, and generate a first polarization component and a second polarization component with mutually orthogonal polarizations;
the second polarization path selection module PPSM2 is configured to perform polarization beam splitting on the quantum state input to the first port thereof, and generate a third polarization component and a fourth polarization component with mutually orthogonal polarizations;
the beam splitter BS is configured to interfere the first polarization component and the third polarization component having the same polarization state, and generate a first interference result and a second interference result; and the second polarization component and the fourth polarization component which have the same polarization state are used for interference, and a third interference result and a fourth interference result are generated;
the first polarization path selection module PPSM1 is further configured to perform polarization beam combination on the first interference result and the third interference result, so as to generate a first bell state measurement result; the second polarization path selection module PPSM2 is further configured to perform polarization beam combination on the second interference result and the fourth interference result, so as to generate a second bell state measurement result;
the first single photon detector SPD1 is configured to detect a first bell state measurement result; the second single photon detector SPD2 is configured to detect a second bell state measurement result.
Preferably, the quantum state preparation module includes: the laser LD, the intensity modulator IM, the time phase coding module and the adjustable attenuator VOA are sequentially connected;
the laser LD is used for generating an optical pulse signal;
the intensity modulator IM is used for modulating the intensity of the optical pulse signal to generate a signal state and a decoy state;
the time phase encoding module is used for randomly generating 4 time phase encoding states;
the adjustable attenuator VOA is used for attenuating the time phase coded state optical signal to a single photon magnitude to generate a quantum state.
Preferably, the first polarization path selection module PPSM1 includes a first circulator CIR1 and a first polarization beam splitter PBS1, and a first port and a third port of the first circulator CIR1 are respectively used as a first port and a fourth port of the first polarization path selection module PPSM 1; the second port of the first circulator CIR1 is connected to the first port of the first polarizing beam splitter PBS 1; the second port and the third port of the first polarization beam splitter PBS1 are respectively used as the second port and the third port of the first polarization path selection module PPSM 1;
the first polarization beam splitter PBS1 is used for horizontally polarizing both the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof when exiting from the second port and the third port thereof, respectively;
the second polarization path selection module PPSM2 comprises a second circulator CIR2 and a second polarization beam splitter PBS2, and a first port and a third port of the second circulator CIR2 are respectively used as a first port and a fourth port of the second polarization path selection module PPSM 2; the second port of the second circulator CIR2 is connected to the first port of the second polarizing beam splitter PBS 2; the second port and the third port of the second polarization beam splitter PBS2 are respectively used as the second port and the third port of the second polarization path selection module PPSM 2;
the second polarizing beam splitter PBS2 is used to horizontally polarize both the vertically polarized component and the horizontally polarized component of the polarization state of the optical signal incident on the first port thereof when exiting from the second port and the third port thereof, respectively.
Preferably, the first polarization path selection module PPSM1 is a third polarization beam splitter PBS3, and the first port to the fourth port of the third polarization beam splitter PBS3 are respectively used as the first port to the fourth port of the first polarization path selection module PPSM 1;
the third polarizing beam splitter PBS3 is used for making the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof still be vertical polarization and horizontal polarization respectively when exiting from the second port and the third port thereof;
the second polarization path selection module PPSM2 is a fourth polarization beam splitter PBS4, and the first port to the fourth port of the fourth polarization beam splitter PBS4 are respectively used as the first port to the fourth port of the second polarization path selection module PPSM 2;
the fourth polarizing beam splitter PBS4 is used to make the vertically polarized component and the horizontally polarized component of the polarization state of the optical signal incident to the first port thereof still vertically polarized and horizontally polarized, respectively, when exiting from the second port and the third port thereof, respectively.
Preferably, the lengths of the first polarization maintaining optical fiber and the second polarization maintaining optical fiber are equal; the lengths of the third polarization maintaining optical fiber and the fourth polarization maintaining optical fiber are equal.
Preferably, the lengths of the first polarization maintaining optical fiber, the second polarization maintaining optical fiber, the third polarization maintaining optical fiber and the fourth polarization maintaining optical fiber are all equal.
Preferably, the beam splitter BS is a polarization maintaining beam splitter operating with a single polarization.
Preferably, the beam splitter BS is a polarization maintaining beam splitter operating with dual polarization.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a measurement equipment irrelevant quantum key distribution system for immune channel disturbance, which adds a depolarization module on a sender, simultaneously performs polarization beam splitting on a measurer, and performs polarization beam combination after interference of orthogonal polarization component bidirectional multiplexing beam splitters, so that the influence of the polarization disturbance of the immune channel of a Bell state measurement result can be greatly improved, and the stability of the system is greatly improved; active polarization compensation is not needed, and only two single photon detectors are needed, so that the complexity and cost of the system are reduced.
Drawings
FIG. 1 is a schematic block diagram of a measurement device independent quantum key distribution system for immune channel perturbation of the present invention;
FIG. 2 is a schematic block diagram of a first embodiment of a measurement device independent quantum key distribution system for immune channel perturbation of the present invention;
fig. 3 is a schematic block diagram of a second embodiment of a measurement device independent quantum key distribution system for immune channel perturbation of the present invention.
Detailed Description
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown.
As shown in fig. 1, a measurement device independent quantum key distribution system for immune channel perturbation includes a first sender 100, a second sender 200, and a measurer 300; the first sender 100 and the second sender 200 are respectively connected with the measuring party 300 through a first fiber channel and a second fiber channel;
the first sender 100 and the second sender 200 both contain a quantum state preparation module and a depolarization module DEP;
the quantum state preparation module is used for generating a quantum state of time phase coding;
the depolarization module DEP is used for reducing the polarization degree of the quantum state to be close to 0 and outputting the polarization degree to a fiber channel;
the measuring party 300 comprises a first polarization path selection module PPSM1, a second polarization path selection module PPSM2, a beam splitter BS, a first single photon detector SPD1 and a second single photon detector SPD2; the first port of the first polarization path selection module PPSM1 and the first port of the second polarization path selection module PPSM2 are respectively used as two input ports of the measuring party 300; the second port of the first polarization path selection module PPSM1 is correspondingly connected with the first port and the fourth port of the beam splitter BS respectively through a first polarization maintaining optical fiber and the second port of the second polarization path selection module PPSM2 through a second polarization maintaining optical fiber; the third port of the first polarization path selection module PPSM1 is correspondingly connected with the second port and the third port of the beam splitter BS respectively through a third polarization maintaining optical fiber and the third port of the second polarization path selection module PPSM2 through a fourth polarization maintaining optical fiber; the fourth port of the first polarization path selection module PPSM1 and the fourth port of the second polarization path selection module PPSM2 are respectively correspondingly connected with the first single photon detector SPD1 and the second single photon detector SPD2;
the first polarization path selection module PPSM1 is configured to perform polarization beam splitting on a quantum state input to a first port thereof, and generate a first polarization component and a second polarization component with mutually orthogonal polarizations;
the second polarization path selection module PPSM2 is configured to perform polarization beam splitting on the quantum state input to the first port thereof, and generate a third polarization component and a fourth polarization component with mutually orthogonal polarizations;
the beam splitter BS is configured to interfere the first polarization component and the third polarization component having the same polarization state, and generate a first interference result and a second interference result; and the second polarization component and the fourth polarization component which have the same polarization state are used for interference, and a third interference result and a fourth interference result are generated;
the first polarization path selection module PPSM1 is further configured to perform polarization beam combination on the first interference result and the third interference result, so as to generate a first bell state measurement result; the second polarization path selection module PPSM2 is further configured to perform polarization beam combination on the second interference result and the fourth interference result, so as to generate a second bell state measurement result;
the first single photon detector SPD1 is configured to detect a first bell state measurement result; the second single photon detector SPD2 is configured to detect a second bell state measurement result.
The specific working process is as follows:
the quantum state preparation module of the first sender 100 randomly prepares 4 time-phase encoded quantum states Q1, reduces the polarization degree to approximately 0 through the depolarization module DEP, and finally enters the first optical fiber channel. Similarly, the second sender 200 randomly prepares the time-phase encoded quantum state Q2 into the second fibre channel through the same process.
At the measuring side 300, the quantum state Q1 prepared by the first transmitting side 100 and the quantum state Q2 prepared by the second transmitting side 200 simultaneously enter the first port of the first polarization path selection module PPSM1 and the first port of the second polarization path selection module PPSM2, respectively. Q1 is divided into a first polarized component and a second polarized component by a first polarized path selection module PPSM1, and the first polarized component and the second polarized component are emitted from a second port and a third port of the first polarized path selection module PPSM1 respectively; q2 is split into a third polarization component and a fourth polarization component by the second polarization path selection module PPSM2, and exits from the second port and the third port of the second polarization path selection module PPSM2, respectively.
The first polarization component reaches the first port of the beam splitter BS through the first polarization maintaining fiber, the third polarization component reaches the fourth port of the beam splitter BS through the second polarization maintaining fiber, and the first polarization component and the third polarization component enter the beam splitter BS to interfere at the same time, so that a first interference result and a second interference result are generated. The first interference result is emitted from the second port of the beam splitter BS and reaches the third port of the first polarization path selection module PPSM1 through the third polarization maintaining fiber; the second interference result exits from the third port of the beam splitter BS and reaches the third port of the second polarization path selection module PPSM2 through the fourth polarization maintaining fiber.
The second polarization component reaches the second port of the beam splitter BS through the third polarization maintaining fiber, the fourth polarization component reaches the third port of the beam splitter BS through the fourth polarization maintaining fiber, and the second polarization component and the fourth polarization component enter the beam splitter BS to interfere at the same time, so that a third interference result and a fourth interference result are generated. The third interference result is emitted from a first port of the beam splitter BS and reaches a second port of the first polarization path selection module PPSM1 through the first polarization maintaining fiber; the fourth interference result exits from the fourth port of the beam splitter BS and reaches the second port of the second polarization path selection module PPSM2 via the second polarization maintaining fiber.
The first interference result and the third interference result enter a first polarization path selection module PPSM1 to carry out polarization beam combination at the same time, a first Bell state measurement result is generated, and the first single photon measurement result enters a first single photon detector SPD1 to carry out detection; and the second interference result and the fourth interference result enter a second polarization path selection module PPSM2 to carry out polarization beam combination, a second Bell state measurement result is generated, and the second single photon measurement result enters a second single photon detector SPD2 to carry out detection. The measuring party 300 publishes the response results of the first single photon detector SPD1 and the second single photon detector SPD2 to the first transmitting party 100 and the second transmitting party 200, and can execute processes such as base pairing, post processing, and the like according to the measurement device independent quantum key distribution protocol, and finally generates a security key.
As shown in fig. 2, in a first embodiment of the present invention:
the structure of the immune channel disturbance measurement equipment independent quantum key distribution system is as follows: the quantum state preparation module comprises: the laser LD, the intensity modulator IM, the time phase coding module and the adjustable attenuator VOA are sequentially connected;
the laser LD is used for generating an optical pulse signal;
the intensity modulator IM is used for modulating the intensity of the optical pulse signal to generate a signal state and a decoy state;
the time phase encoding module is used for randomly generating 4 time phase encoding states;
the adjustable attenuator VOA is used for attenuating the time phase coded state optical signal to a single photon magnitude to generate a quantum state;
the first polarization path selection module PPSM1 comprises a first circulator CIR1 and a first polarization beam splitter PBS1, and a first port and a third port of the first circulator CIR1 are respectively used as a first port and a fourth port of the first polarization path selection module PPSM 1; the second port of the first circulator CIR1 is connected to the first port of the first polarizing beam splitter PBS 1; the second port and the third port of the first polarization beam splitter PBS1 are respectively used as the second port and the third port of the first polarization path selection module PPSM 1;
the first polarization beam splitter PBS1 is used for horizontally polarizing both the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof when exiting from the second port and the third port thereof, respectively;
the second polarization path selection module PPSM2 comprises a second circulator CIR2 and a second polarization beam splitter PBS2, and a first port and a third port of the second circulator CIR2 are respectively used as a first port and a fourth port of the second polarization path selection module PPSM 2; the second port of the second circulator CIR2 is connected to the first port of the second polarizing beam splitter PBS 2; the second port and the third port of the second polarization beam splitter PBS2 are respectively used as the second port and the third port of the second polarization path selection module PPSM 2;
the second polarizing beam splitter PBS2 is used to horizontally polarize both the vertically polarized component and the horizontally polarized component of the polarization state of the optical signal incident on the first port thereof when exiting from the second port and the third port thereof, respectively.
The lengths of the first polarization maintaining optical fiber and the second polarization maintaining optical fiber are equal; the lengths of the third polarization maintaining optical fiber and the fourth polarization maintaining optical fiber are equal;
the beam splitter BS is a polarization-preserving beam splitter operating with a single polarization.
A specific working procedure of the embodiment is as follows:
the optical pulse signal generated by the laser LD of the first sender 100 is randomly modulated into a signal state or a decoy state by the intensity modulator IM, then enters the time phase encoding module, randomly prepares 4 time-phase encoding states, is attenuated to a single photon magnitude by the adjustable attenuator VOA to become a time phase encoding quantum state Q1, reduces the polarization degree to be close to 0 by the depolarization module DEP, and finally enters the first optical fiber channel. Similarly, the second sender 200 randomly prepares the time-phase encoded quantum state Q2 into the second fibre channel through the same process.
At the measuring part 300, the quantum state Q1 prepared by the first transmitting part 100 and the quantum state Q2 prepared by the second transmitting part 200 simultaneously enter the first port of the first circulator CIR1 and the first port of the second circulator CIR2 respectively. The Q1 exits from the second port of the first circulator CIR1, is divided into a first polarization component and a second polarization component by the first polarization beam splitter PBS1, and exits from the second port and the third port of the first polarization beam splitter PBS1 respectively; q2 exits from the second port of the second circulator CIR2, is split into a third polarization component and a fourth polarization component by the second polarization beam splitter PBS2, and exits from the second port and the third port of the second polarization beam splitter PBS2, respectively.
The first polarization component propagates along the first polarization-maintaining optical fiber slow axis to reach the first port of the beam splitter BS, the third polarization component propagates along the second polarization-maintaining optical fiber slow axis to reach the fourth port of the beam splitter BS, and the first polarization component and the third polarization component enter the beam splitter BS to interfere at the same time, so that a first interference result and a second interference result are generated. The first interference result exits from the second port of the beam splitter BS and propagates along the third polarization maintaining fiber slow axis to reach the third port of the first polarization beam splitter PBS 1; the second interference result exits from the third port of the beam splitter BS, propagates along the fourth polarization maintaining fiber slow axis, and reaches the third port of the second polarization beam splitter PBS 2.
The second polarization component propagates along the third polarization maintaining optical fiber slow axis to reach the second port of the beam splitter BS, and the fourth polarization component propagates along the fourth polarization maintaining optical fiber slow axis to reach the third port of the beam splitter BS, and both enter the beam splitter BS to interfere at the same time, so as to generate a third interference result and a fourth interference result. The third interference result exits from the first port of the beam splitter BS and propagates along the first polarization maintaining optical fiber slow axis to reach the second port of the first polarization beam splitter PBS 1; the fourth interference result exits from the fourth port of the beam splitter BS, propagates along the second polarization maintaining fiber slow axis, and reaches the second port of the second polarization beam splitter PBS 2.
The first interference result and the third interference result enter a first polarization beam splitter PBS1 to carry out polarization beam combination at the same time, a first Bell state measurement result is generated, and the first Bell state measurement result enters a first single photon detector SPD1 to be detected through a first circulator CIR 1; and the second interference result and the fourth interference result enter a second polarization beam splitter PBS2 to carry out polarization beam combination, a second Bell state measurement result is generated, and the second Bell state measurement result enters a second single photon detector SPD2 to be detected through a second circulator CIR 2. The measuring party 300 publishes the response results of the first single photon detector SPD1 and the second single photon detector SPD2 to the first transmitting party 100 and the second transmitting party 200, and can execute processes such as base pairing, post processing, and the like according to the measurement device independent quantum key distribution protocol, and finally generates a security key.
As shown in fig. 3, in a second embodiment of the present invention:
the structure of the immune channel disturbance measurement equipment independent quantum key distribution system is as follows: the quantum state preparation module comprises: the laser LD, the intensity modulator IM, the time phase coding module and the adjustable attenuator VOA are sequentially connected;
the laser LD is used for generating an optical pulse signal;
the intensity modulator IM is used for modulating the intensity of the optical pulse signal to generate a signal state and a decoy state;
the time phase encoding module is used for randomly generating 4 time phase encoding states;
the adjustable attenuator VOA is used for attenuating the time phase coded state optical signal to a single photon magnitude to generate a quantum state;
the first polarization path selection module PPSM1 is a third polarization beam splitter PBS3, and the first port to the fourth port of the third polarization beam splitter PBS3 are respectively used as the first port to the fourth port of the first polarization path selection module PPSM 1;
the third polarizing beam splitter PBS3 is used for making the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof still be vertical polarization and horizontal polarization respectively when exiting from the second port and the third port thereof;
the second polarization path selection module PPSM2 is a fourth polarization beam splitter PBS4, and the first port to the fourth port of the fourth polarization beam splitter PBS4 are respectively used as the first port to the fourth port of the second polarization path selection module PPSM 2;
the fourth polarizing beam splitter PBS4 is used for respectively making the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof still respectively vertical polarization and horizontal polarization when exiting from the second port and the third port thereof;
the lengths of the first polarization maintaining optical fiber, the second polarization maintaining optical fiber, the third polarization maintaining optical fiber and the fourth polarization maintaining optical fiber are equal;
the beam splitter BS is a polarization-preserving beam splitter operating with dual polarization.
The specific working procedure of the second embodiment is as follows:
the optical pulse signal generated by the laser LD of the first sender 100 is randomly modulated into a signal state or a decoy state by the intensity modulator IM, then enters the time phase encoding module, randomly prepares 4 time-phase encoding states, is attenuated to a single photon magnitude by the adjustable attenuator VOA to become a time phase encoding quantum state Q1, reduces the polarization degree to be close to 0 by the depolarization module DEP, and finally enters the first optical fiber channel. Similarly, the second sender 200 randomly prepares the time-phase encoded quantum state Q2 into the second fibre channel through the same process.
At the measuring side 300, the quantum state Q1 prepared by the first transmitting side 100 and the quantum state Q2 prepared by the second transmitting side 200 simultaneously enter the first port of the third polarizing beam splitter PBS3 and the first port of the fourth polarizing beam splitter PBS4, respectively. The Q1 is divided into a first polarized component and a second polarized component by a third polarized beam splitter PBS3, and the first polarized component and the second polarized component respectively exit from a second port and a third port of the third polarized beam splitter PBS 3; q2 is split into a third polarization component and a fourth polarization component by the fourth polarization beam splitter PBS4, and exits from the second port and the third port of the fourth polarization beam splitter PBS4, respectively.
The first polarization component propagates along the first polarization-maintaining optical fiber fast axis to reach the first port of the beam splitter BS, the third polarization component propagates along the second polarization-maintaining optical fiber fast axis to reach the fourth port of the beam splitter BS, and the first polarization component and the third polarization component enter the beam splitter BS to interfere at the same time, so that a first interference result and a second interference result are generated. The first interference result exits from the second port of the beam splitter BS and propagates along the third polarization maintaining fiber fast axis to reach the third port of the third polarization beam splitter PBS 3; the second interference result exits from the third port of the beam splitter BS and propagates along the fourth polarization maintaining fiber fast axis to the third port of the fourth polarization beam splitter PBS 4.
The second polarization component propagates along the third polarization maintaining optical fiber slow axis to reach the second port of the beam splitter BS, and the fourth polarization component propagates along the fourth polarization maintaining optical fiber slow axis to reach the third port of the beam splitter BS, and both enter the beam splitter BS to interfere at the same time, so as to generate a third interference result and a fourth interference result. The third interference result exits from the first port of the beam splitter BS and propagates along the first polarization-preserving optical fiber slow axis to reach the second port of the third polarization beam splitter PBS 3; the fourth interference result exits from the fourth port of the beam splitter BS, propagates along the second polarization maintaining fiber slow axis, and reaches the second port of the fourth polarization beam splitter PBS 4.
The first interference result and the third interference result enter the third polarization beam splitter PBS3 to carry out polarization beam combination, a first Bell state measurement result is generated, and the first Bell state measurement result enters the first single photon detector SPD1 to be detected after exiting from the fourth port of the third polarization beam splitter PBS 3; the second interference result and the fourth interference result enter the fourth polarization beam splitter PBS4 to carry out polarization beam combination, a second Bell state measurement result is generated, and the second single photon detector SPD2 enters the fourth port of the fourth polarization beam splitter PBS4 to carry out detection. The measuring party 300 publishes the response results of the first single photon detector SPD1 and the second single photon detector SPD2 to the first transmitting party 100 and the second transmitting party 200, and can execute processes such as base pairing, post processing, and the like according to the measurement device independent quantum key distribution protocol, and finally generates a security key.
By integrating the embodiments of the invention, the invention provides an immune channel disturbance measurement equipment independent quantum key distribution system, which adds a depolarization module on a sender, simultaneously performs polarization beam splitting on a measurer, and performs polarization beam combination after interference of orthogonal polarization component bidirectional multiplexing beam splitters, so that the influence of the Bell state measurement result immune channel polarization disturbance can be greatly improved, and the stability of the system is greatly improved; active polarization compensation is not needed, and only two single photon detectors are needed, so that the complexity and cost of the system are reduced.
Claims (8)
1. A measurement device independent quantum key distribution system of immune channel perturbation, characterized by comprising a first sender (100), a second sender (200) and a measuring party (300); the first sender (100) and the second sender (200) are respectively connected with the measuring party (300) through a first fiber channel and a second fiber channel;
the first sender (100) and the second sender (200) both comprise a quantum state preparation module and a depolarization module DEP;
the quantum state preparation module is used for generating a quantum state of time phase coding;
the depolarization module DEP is used for reducing the polarization degree of the quantum state to be close to 0 and outputting the polarization degree to a fiber channel;
the measuring party (300) comprises a first polarization path selection module (PPSM 1), a second polarization path selection module (PPSM 2), a Beam Splitter (BS), a first single photon detector (SPD 1) and a second single photon detector (SPD 2); the first port of the first polarization path selection module PPSM1 and the first port of the second polarization path selection module PPSM2 are respectively used as two input ports of a measuring party (300); the second port of the first polarization path selection module PPSM1 is correspondingly connected with the first port and the fourth port of the beam splitter BS respectively through a first polarization maintaining optical fiber and the second port of the second polarization path selection module PPSM2 through a second polarization maintaining optical fiber; the third port of the first polarization path selection module PPSM1 is correspondingly connected with the second port and the third port of the beam splitter BS respectively through a third polarization maintaining optical fiber and the third port of the second polarization path selection module PPSM2 through a fourth polarization maintaining optical fiber; the fourth port of the first polarization path selection module PPSM1 and the fourth port of the second polarization path selection module PPSM2 are respectively correspondingly connected with the first single photon detector SPD1 and the second single photon detector SPD2;
the first polarization path selection module PPSM1 is configured to perform polarization beam splitting on a quantum state input to a first port thereof, and generate a first polarization component and a second polarization component with mutually orthogonal polarizations;
the second polarization path selection module PPSM2 is configured to perform polarization beam splitting on the quantum state input to the first port thereof, and generate a third polarization component and a fourth polarization component with mutually orthogonal polarizations;
the beam splitter BS is configured to interfere the first polarization component and the third polarization component having the same polarization state, and generate a first interference result and a second interference result; and the second polarization component and the fourth polarization component which have the same polarization state are used for interference, and a third interference result and a fourth interference result are generated;
the first polarization path selection module PPSM1 is further configured to perform polarization beam combination on the first interference result and the third interference result, so as to generate a first bell state measurement result; the second polarization path selection module PPSM2 is further configured to perform polarization beam combination on the second interference result and the fourth interference result, so as to generate a second bell state measurement result;
the first single photon detector SPD1 is configured to detect a first bell state measurement result; the second single photon detector SPD2 is configured to detect a second bell state measurement result.
2. The immune channel perturbation measurement device-independent quantum key distribution system of claim 1, wherein the quantum state preparation module comprises: the laser LD, the intensity modulator IM, the time phase coding module and the adjustable attenuator VOA are sequentially connected;
the laser LD is used for generating an optical pulse signal;
the intensity modulator IM is used for modulating the intensity of the optical pulse signal to generate a signal state and a decoy state;
the time phase encoding module is used for randomly generating 4 time phase encoding states;
the adjustable attenuator VOA is used for attenuating the time phase coded state optical signal to a single photon magnitude to generate a quantum state.
3. The measurement device independent quantum key distribution system of immune channel perturbation according to claim 1 or 2, wherein the first polarization path selection module PPSM1 comprises a first circulator CIR1 and a first polarization beam splitter PBS1, the first port and the third port of the first circulator CIR1 being the first port and the fourth port of the first polarization path selection module PPSM1, respectively; the second port of the first circulator CIR1 is connected to the first port of the first polarizing beam splitter PBS 1; the second port and the third port of the first polarization beam splitter PBS1 are respectively used as the second port and the third port of the first polarization path selection module PPSM 1;
the first polarization beam splitter PBS1 is used for horizontally polarizing both the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof when exiting from the second port and the third port thereof, respectively;
the second polarization path selection module PPSM2 comprises a second circulator CIR2 and a second polarization beam splitter PBS2, and a first port and a third port of the second circulator CIR2 are respectively used as a first port and a fourth port of the second polarization path selection module PPSM 2; the second port of the second circulator CIR2 is connected to the first port of the second polarizing beam splitter PBS 2; the second port and the third port of the second polarization beam splitter PBS2 are respectively used as the second port and the third port of the second polarization path selection module PPSM 2;
the second polarizing beam splitter PBS2 is used to horizontally polarize both the vertically polarized component and the horizontally polarized component of the polarization state of the optical signal incident on the first port thereof when exiting from the second port and the third port thereof, respectively.
4. The measurement device independent quantum key distribution system for immune channel perturbation according to claim 1 or 2, wherein the first polarization path selection module PPSM1 is a third polarization beam splitter PBS3, and the first port to the fourth port of the third polarization beam splitter PBS3 are respectively used as the first port to the fourth port of the first polarization path selection module PPSM 1;
the third polarizing beam splitter PBS3 is used for making the vertical polarization component and the horizontal polarization component of the polarization state of the optical signal incident to the first port thereof still be vertical polarization and horizontal polarization respectively when exiting from the second port and the third port thereof;
the second polarization path selection module PPSM2 is a fourth polarization beam splitter PBS4, and the first port to the fourth port of the fourth polarization beam splitter PBS4 are respectively used as the first port to the fourth port of the second polarization path selection module PPSM 2;
the fourth polarizing beam splitter PBS4 is used to make the vertically polarized component and the horizontally polarized component of the polarization state of the optical signal incident to the first port thereof still vertically polarized and horizontally polarized, respectively, when exiting from the second port and the third port thereof, respectively.
5. The immune channel perturbation measurement device independent quantum key distribution system of claim 1, wherein the first and second polarization maintaining fibers are equal in length; the lengths of the third polarization maintaining optical fiber and the fourth polarization maintaining optical fiber are equal.
6. The immune channel perturbation measurement device-independent quantum key distribution system of claim 1, wherein the first polarization maintaining fiber, the second polarization maintaining fiber, the third polarization maintaining fiber, and the fourth polarization maintaining fiber are all equal in length.
7. The immune channel perturbation measuring device independent quantum key distribution system of claim 3, wherein the beam splitter BS is a single polarization operated polarization maintaining beam splitter.
8. The immune channel perturbation measuring device independent quantum key distribution system of claim 4, wherein the beam splitter BS is a dual polarization operated polarization preserving beam splitter.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113225184A (en) * | 2021-05-11 | 2021-08-06 | 中国人民解放军空军工程大学 | Passive decoy state modulation reference system-independent quantum key distribution system and method |
| CN114080781A (en) * | 2019-06-17 | 2022-02-22 | 株式会社Kt | Quantum key distribution method, device and system |
| CN114338020A (en) * | 2022-03-15 | 2022-04-12 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution coding device |
| EP4099585A1 (en) * | 2021-05-31 | 2022-12-07 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Quantum key distribution with active sagnac interferometer |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110048841A (en) * | 2019-05-24 | 2019-07-23 | 浙江九州量子信息技术股份有限公司 | A kind of simple polarization encoder quantum key distribution system and method |
| CN110324145A (en) * | 2019-08-08 | 2019-10-11 | 赵义博 | It is a kind of to polarize unrelated phase code quantum key distribution system and method |
| WO2021188045A1 (en) * | 2020-03-17 | 2021-09-23 | Nanyang Technological University | System and apparatuses for measurement-device-independent quantum key distribution |
| CN113347005A (en) * | 2021-07-17 | 2021-09-03 | 神盾迅波(北京)量子科技发展有限公司 | Polarization disturbance resistant quantum digital signature system |
| CN114553421B (en) * | 2022-04-25 | 2022-08-02 | 北京中科国光量子科技有限公司 | Quantum key distribution decoding device for immune channel disturbance |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114080781A (en) * | 2019-06-17 | 2022-02-22 | 株式会社Kt | Quantum key distribution method, device and system |
| CN113225184A (en) * | 2021-05-11 | 2021-08-06 | 中国人民解放军空军工程大学 | Passive decoy state modulation reference system-independent quantum key distribution system and method |
| EP4099585A1 (en) * | 2021-05-31 | 2022-12-07 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Quantum key distribution with active sagnac interferometer |
| CN114338020A (en) * | 2022-03-15 | 2022-04-12 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution coding device |
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