CN109379188B - Measuring equipment irrelevant phase matching quantum key distribution device - Google Patents
Measuring equipment irrelevant phase matching quantum key distribution device Download PDFInfo
- Publication number
- CN109379188B CN109379188B CN201811506414.6A CN201811506414A CN109379188B CN 109379188 B CN109379188 B CN 109379188B CN 201811506414 A CN201811506414 A CN 201811506414A CN 109379188 B CN109379188 B CN 109379188B
- Authority
- CN
- China
- Prior art keywords
- phase
- beam splitter
- communication
- optical
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- 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
- H04L9/0858—Details about key distillation or coding, e.g. reconciliation, error correction, privacy amplification, polarisation coding or phase coding
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- 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
- H04L9/0819—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)
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Theoretical Computer Science (AREA)
- Optical Communication System (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The invention discloses a measuring equipment irrelevant phase matching quantum key distribution device, in particular to a measuring equipment irrelevant quantum key distribution scheme based on phase coding. Both legal communication parties encode phase information on the optical field and then send the phase information to a third party for first-order interferometry. The invention introduces reference phase information, thereby avoiding using global phase and not needing to carry out phase locking of the laser. The reference phase information may be provided by a third party, or may be obtained by the third party measuring the phase reference pulse transmitted by both parties.
Description
Technical Field
The application relates to the field of quantum key distribution, in particular to a measuring equipment irrelevant phase matching quantum key distribution device.
Background
The one-time pad encryption algorithm is a communication method which is known to be proved to be absolutely secure at present, but because a large number of keys are consumed in the communication process, the key for guaranteeing the secure distribution of the keys becomes the key for guaranteeing the communication security. Quantum key distribution based on the quantum mechanics rationale can achieve key distribution with provable security. Since the first quantum key distribution scheme was proposed in 1984, a plurality of key distribution schemes have been proposed, and some of the schemes have been commercialized. However, the further improvement of the communication distance and code rate of quantum key distribution is limited by factors such as channel loss and detector quantum efficiency. The current experimental farthest communication distance is 1200 km in free space and the optical fiber system is 421 km. Further increasing the communication distance requires the use of quantum repeaters, but quantum repeaters require long-term quantum storage and high fidelity, which are difficult to achieve experimentally.
The recently proposed measurement equipment irrelevant phase matching quantum key distribution scheme (also called Twin-Field quantum key distribution scheme) utilizes two coherent light fields to perform first-order interference code formation, breaks through the previous limitation on the quantum key distribution communication distance, and in the scheme, the code rate and the communication distance (or channel loss) evolution party are in a direct proportion relation, so that the communication distance and the code rate are greatly improved. However, the scheme requires the lasers of both communication parties to carry out phase locking, so that the experimental difficulty is greatly increased. Therefore, a more easily implementable protocol is needed.
Disclosure of Invention
The invention provides a measuring equipment irrelevant phase matching quantum key distribution method, which is used for solving the problems of short communication distance and low code rate of quantum key distribution.
In order to achieve the above technical object, the present invention provides a measuring device-independent phase matching quantum key distribution apparatus, including:
the first communication terminal and the second communication terminal which are legal and the third party detection terminal which is not trusted;
the first communication end and the second communication end are used for quantum state preparation and respectively comprise a phase modulator and an optical attenuator; the first communication end and the second communication end perform phase modulation on the signal pulse light through the phase modulator according to the executed quantum key distribution protocol, and the modulation mode of the phase modulator comprises a random switching coding mode and a decoy mode; the pulse light after phase modulation is attenuated to the appointed pulse intensity by an optical attenuator;
the third-party detection end is used for performing first-order interferometry and comprises a beam splitter, a first single photon measurer and a second single photon measurer; the first communication end and the second communication end send the prepared optical pulse signals to the third-party detection end, the first-order interference measurement is carried out by sending the optical pulse signals to the beam splitter, two optical pulses of the result are output, the two optical pulses are respectively received by the first single-photon detector and the second single-photon detector for measurement, and the measurement result is published.
The phase modulators of the first communication end and the second communication end are respectively provided with a light source in front, and the light sources are used for generating signal light pulses according to an executed quantum key distribution protocol.
The third party detection end is provided with a first optical switch and a second optical switch which respectively and correspondingly receive optical pulses transmitted by the first communication end and the second communication end; and a second phase modulator is arranged between the first optical switch and the beam splitter or between the second optical switch and the beam splitter and is used for carrying out phase compensation so as to eliminate the influence of the initial phase of the pulse.
The third-party detection end further comprises a relative phase measurement module which is respectively connected with the first optical switch and the second optical switch, optical pulse signals generated by the light sources of the first communication end and the second communication end comprise phase reference pulses and measurement signal pulses, the first optical switch and the second optical switch send the phase reference pulses to the relative phase measurement module for measurement, and meanwhile, the measurement signal pulses are sent to the beam splitter for first-order interference.
The light source of the third party detection end is connected with the beam splitter through the first circulator and is divided into two beams through the beam splitter to be respectively sent to the first communication end and the second communication end.
The optical attenuators of the first communication end and the second communication end are respectively connected with a second beam splitter, a part of light formed by the splitting of the second beam splitter enters the phase modulator through the optical attenuators, and an intensity modulator is arranged behind the phase modulator; the light pulse is emitted from the intensity modulator and reflected by the faraday mirror.
The second beam splitters of the first communication end and the second communication end are respectively connected with a photoelectric detector, and the other part of light formed by beam splitting of the second beam splitter is received for detection so as to monitor whether an eavesdropper can inject strong light for eavesdropping.
When the phase modulator selects the encoding mode, the intensity modulator adjusts the pulse intensity to make the rated output intensity of the first communication terminal and the second communication terminal beα|2And encoding the random key by a phase modulator; when the phase modulator chooses to implement the trick mode, the intensity modulator is adjusted according to the trick mode protocol used,and the random phase is encoded through the phase modulator, the encoded light pulse is returned to a third-party detection end, first-order interference is carried out through the beam splitter, and measurement is carried out by using the first single-photon detector and the second single-photon detector.
The light pulse is sent to a second beam splitter through the second circulator and the third circulator in the first communication end and the second communication end, the second beam splitter is connected with an intensity modulator, and a part of light formed by beam splitting of the beam splitter enters the intensity modulator, a phase modulator and an optical attenuator respectively to load trap states and key information; and then the first-order interference is carried out in a beam splitter at a third-party detection end, the output result is received by the first single-photon detector and the second single-photon detector for measurement, and the measurement result is published.
The second beam splitters of the first communication end and the second communication end are respectively connected with a photoelectric detector, and the other part of light formed by beam splitting is detected by the photoelectric detector so as to monitor whether an eavesdropper can inject strong light to perform eavesdropping operation.
Different from the prior art, the invention provides a method for distributing measurement equipment irrelevant phase matching quantum keys, and the communication method and the communication system realize the coding and decoding of the keys by introducing phase reference without carrying out laser phase locking and phase post-selection, thereby greatly reducing the realization difficulty of experiments and improving the code rate; the problem that the phase is needed to be selected after the initial phases of the signal pulses are different is solved, and the code rate can be effectively improved.
Drawings
Fig. 1 is a schematic structural diagram of an embodiment of a measuring device-independent phase matching quantum key distribution apparatus according to the present invention;
fig. 2 is a schematic structural diagram of another embodiment of a measuring device-independent phase matching quantum key distribution apparatus according to the present invention;
fig. 3 is a schematic structural diagram of equipment required for three different ways of preparing a signal light source in the measurement equipment-independent phase matching quantum key distribution device provided by the invention;
fig. 4 is a schematic structural diagram of another embodiment of a measuring device-independent phase matching quantum key distribution apparatus according to the present invention;
fig. 5 is a schematic structural diagram of a measuring device-independent phase matching quantum key distribution apparatus according to still another embodiment of the present invention.
Detailed Description
The invention provides a measuring equipment irrelevant phase matching quantum key distribution device, which comprises:
the first communication terminal and the second communication terminal which are legal and the third party detection terminal which is not trusted;
the first communication end and the second communication end are used for quantum state preparation and comprise a phase modulator and an optical attenuator; the first communication end and the second communication end perform phase modulation on the signal pulse light through the phase modulator according to the executed quantum key distribution protocol, and the modulation mode of the phase modulator comprises a random switching coding mode and a decoy mode; the pulse light after phase modulation is attenuated to the appointed pulse intensity by an optical attenuator;
the third-party detection end is used for performing first-order interferometry and comprises a beam splitter, a first single photon measurer and a second single photon measurer; the first communication end and the second communication end send the prepared optical pulse signals to the third-party detection end, the first-order interference measurement is carried out by sending the optical pulse signals to the beam splitter, two optical pulses of the result are output, the two optical pulses are respectively received by the first single-photon detector and the second single-photon detector for measurement, and the measurement result is published.
The phase modulators of the first communication end and the second communication end are respectively provided with a light source in front, and the light sources are used for generating signal light pulses according to an executed quantum key distribution protocol.
The third party detection end is provided with a first optical switch and a second optical switch which respectively and correspondingly receive optical pulses transmitted by the first communication end and the second communication end; and a second phase modulator is arranged between the first optical switch and the beam splitter or between the second optical switch and the beam splitter and is used for carrying out phase compensation so as to eliminate the influence of the initial phase of the pulse.
The third-party detection end further comprises a relative phase measurement module which is respectively connected with the first optical switch and the second optical switch, optical pulse signals generated by the light sources of the first communication end and the second communication end comprise phase reference pulses and measurement signal pulses, the first optical switch and the second optical switch send the phase reference pulses to the relative phase measurement module for measurement, and meanwhile, the measurement signal pulses are sent to the beam splitter for first-order interference.
The light source of the third party detection end is connected with the beam splitter through the first circulator and is divided into two beams through the beam splitter to be respectively sent to the first communication end and the second communication end.
The optical attenuators of the first communication end and the second communication end are respectively connected with a second beam splitter, a part of light formed by the splitting of the second beam splitter enters the phase modulator through the optical attenuators, and an intensity modulator is arranged behind the phase modulator; the light pulse is emitted from the intensity modulator and reflected by the faraday mirror.
The second beam splitters of the first communication end and the second communication end are respectively connected with a photoelectric detector, and the other part of light formed by beam splitting of the second beam splitter is received for detection so as to monitor whether an eavesdropper can inject strong light for eavesdropping.
When the phase modulator selects the encoding mode, the intensity modulator adjusts the pulse intensity to make the rated output intensity of the first communication terminal and the second communication terminal beα|2And encoding the random key by a phase modulator; when the phase modulator selects to execute a decoy mode, the intensity modulator is adjusted according to the used decoy state protocol, a random phase is encoded through the phase modulator, the encoded light pulse is returned to a third-party detection end, first-order interference is carried out through the beam splitter, and measurement is carried out through the first single-photon detector and the second single-photon detector.
The light pulse is sent to a second beam splitter through the second circulator and the third circulator in the first communication end and the second communication end, the second beam splitter is connected with an intensity modulator, and a part of light formed by beam splitting of the beam splitter enters the intensity modulator, a phase modulator and an optical attenuator respectively to load trap states and key information; and then the first-order interference is carried out in a beam splitter at a third-party detection end, the output result is received by the first single-photon detector and the second single-photon detector for measurement, and the measurement result is published.
The second beam splitters of the first communication end and the second communication end are respectively connected with a photoelectric detector, and the other part of light formed by beam splitting is detected by the photoelectric detector so as to monitor whether an eavesdropper can inject strong light to perform eavesdropping operation.
The following are various embodiments provided for the present invention. In the following embodiment, the first communication terminal and the second communication terminal are represented by Alice and Bob which are both legally communicating, and the third party detecting terminal is represented by an untrusted third party Charlie.
The protocol involved describes:
1. the two parties of legal communication, Alice and Bob, respectively, randomly select a coding mode (X basis) and a decoy mode (Z basis).
2. Upon selection of the decoy mode (Z-basis), alice (bob) prepares coherent light pulses with random phases. The pulse intensity is determined according to the spoof state protocol used.
3. Upon selection of the encoding mode (X-basis), alice (bob) encodes phase information according to the transmitted key information. For example, as 0 or pi, corresponding to 0 or 1 bit, respectively.
And 4, sending the prepared quantum state to an untrusted third party Charlie by Alice and Bob. Charlie performs interferometric measurement on the pulse signal after receiving the pulse signal, and publishes the measurement result.
In the protocol, when Alice (Bob) selects the encoding mode (X basis), it needs to encode 0 or pi phase, and therefore, Alice and Bob need to share one reference phase. The reference phase can be realized by phase locking two lasers, but the experimental realization difficulty is larger.
The first embodiment: fig. 1 is a schematic diagram of an architecture of a measuring device-independent phase matching quantum key distribution apparatus.
As shown in fig. 1, the quantum key distribution system 100 uses a strongly attenuated laser as communication light, and may include Alice 110 and Bob 120, which are legitimate communication parties, and an untrusted third party Charlie 130. The quantum state preparation performed by Alice 110 and Bob 120 of the two parties of the legal communication may be composed of light sources 111 (121), phase modulators 112 (122), and optical attenuators 113 (123). The third party Charlie 130, as a measuring end, performs first-order interferometric measurement, and may be composed of optical switches 131 and 132, a relative phase measuring module 133, a beam splitter 136, a first single-photon detector 134, and a second single-photon detector 135. The optical switches 132 and 132 correspond to the first optical switch and the second optical switch, and since the functions of the two switches are the same, they are distinguished only by reference numerals and not by names in the drawings.
The light source 111 (121) generates phase reference pulsed light and signal pulsed light according to the executed quantum key distribution protocol, and phase modulates the signal pulses by the phase modulator 112 (122). Assuming that the initial phases of the phase reference pulse and the signal pulse are respectivelyΦ 0AndΨ 0. The phase modulator 112 (122) randomly switches the encoding mode (X-base) in which the phase 0 or pi is randomly encoded and the decoy mode (Z-base) in which the phase is randomly encodedθ，θE 0,2 pi), where theta may be continuously distributed from 0 to 2 pi, or may take several discrete values fixed. The phase-modulated optical pulses are attenuated to a suitable pulse intensity by the optical attenuator 113 (123). Then, both communication parties send the prepared optical pulse signals to an untrusted third party Charlie 130, and after receiving the optical pulse signals, the Charlie sends phase reference pulses to a relative phase measurement module 133 through an optical switch, and performs relative phase measurement on the phase reference pulses sent by Alice 110 and Bob 120. The signal pulses are sent by the optical switch to the beam splitter 136 for first order interferometry measurements, interference outputsAnd the output is measured by two single photon detectors. After the measurement is completed, Charlie 130 publishes all measurements, including the relative phase of the phase reference pulse and the interferometric measurement of the signal pulse.
Since the pair of phase reference pulse and signal pulse transmitted by Alice 110 (Bob 120) are prepared from the same optical source, their initial phases have a fixed phase difference, and after being transmitted through the optical fiber, the channel changes the phases of both because they travel the same propagation path. The relative initial phase of the signal pulses can be obtained by measuring the relative phases of the phase reference pulses transmitted by Alice and Bob. Since the light sources of Alice 110 and Bob 120 are not initially phase locked, they are completely random with respect to the initial phase, and only signal pulses with the same or similar initial phases are selected for encoding. It should be noted that this approach has an inherent bit error rate because the relative phases are not exactly the same.
The relative phase measurement module 133 of the phase reference pulse may be before the beam splitter 136, as shown in fig. 1, or may be after the beam splitter 136, and accordingly the optical switches 131 and 132 may be placed after the beam splitter 136. This ensures that the phase reference pulse and the signal pulse experience the same optical path.
In this embodiment, the relative phase of the signal pulse can be estimated by measuring the relative phase of the phase reference pulse transmitted by Alice 110 and Bob 120. The phase reference pulse actually establishes a shared reference phase between Alice 110 and Bob 120 and the third party Charlie 130. The solution does not require the light sources of the senders 110 and 120 to have the same initial phase, and does not need to perform phase locking, thereby greatly reducing the requirements of experiments on the light sources.
Second embodiment: fig. 2 is a schematic diagram of an architecture of another embodiment of a measuring device-independent phase matching quantum key distribution apparatus.
As shown in fig. 2, the quantum key distribution system 200 uses a strongly attenuated laser as communication light, and may include Alice 210 and Bob 220, which are legitimate communication parties, and an untrusted third party Charlie 230. The method for Alice 210 (Bob 220) to prepare the pulse signal in this scheme is the same as the scheme shown in fig. 1. After receiving the optical pulse, Charlie 230 sends a phase reference pulse to a relative phase measurement module 233 through a first optical switch 231 and a second optical switch 232, and can estimate an initial phase difference of the signal pulse according to a relative phase measurement result of the phase reference pulse, and Charlie 230 performs phase compensation on the signal pulse sent by Alice 210 or Bob 220 through a second phase modulator 237. The initial phases of the signal pulses are different because the light sources of Alice 210 and Bob 220 are not phase-locked. The phase compensation by the phase modulator 237 can eliminate the influence of the initial phase difference. The phase compensation may be performed on the signal pulses sent by Alice 210, on Bob 220, or both. The phase compensated signal pulses are passed through the beam splitter 236 for first order interferometry. The third party Charlie 230 publishes the measurement result, and the senders 210 and 220 form codes according to the measurement result published by the third party 230, and perform error correction and privacy amplification processes to obtain a final security key.
In this embodiment, the phase of the signal pulse is compensated by the phase modulator 237 after the third party Charlie 230 measures the relative phase of the phase reference pulse. The scheme can eliminate the problem that the phase is required to be selected after the initial phases of the signal pulses are different, and can effectively improve the code rate.
In the first and second embodiments, the light source may be, but is not limited to, a continuous laser that is chopped into pulsed light by external modulation (e.g., using an intensity modulator or amplitude modulator). Fig. 3 shows several possible light source preparation schemes, and the laser light emitted from the continuous laser 311 in fig. 3 (a) is chopped into pulsed light by the intensity modulator 312. Since the phase reference pulse strength is much higher than the signal pulse strength, a high extinction ratio intensity modulator is required. The phase reference pulse and the signal pulse are generated by adjusting the voltage applied to the intensity modulator. Fig. 3 (b) shows another method of generating light pulses. The continuous laser 321 is chopped into pulsed light by the intensity modulator 322, and the pulsed light is split into two beams by the beam splitter 323, wherein one beam of light directly reaches the beam combiner 324 as a phase reference pulse. The other beam is attenuated 325 and delayed to the combiner 324 as a signal pulse. Since the phase reference pulse and the signal pulse are derived from the same optical pulse signal, two pulses with a fixed phase difference can be obtained as long as the delay is guaranteed to be constant. Another possible light source implementation is shown in fig. 3 (c). The extinction ratio is improved by means of a cascade of two intensity modulators 332 and 333.
The third embodiment: fig. 4 is a schematic diagram of an architecture of another embodiment of a measuring device-independent phase matching quantum key distribution system.
The quantum key distribution system 400 shown in fig. 4 uses a strongly attenuated laser as communication light, and may include Alice 410 and Bob 420, which are legitimate communication parties, and an untrusted third party Charlie 430. The solution employs a plug and play architecture, with the light source being provided by the untrusted third party Charlie 430. After passing through the circulator 433, the light source 435 emits pulsed light, which is split into two beams by the beam splitter 431 and sent to the two legitimate parties 410 and 420, respectively. After the light pulses reach 410 and 420, a portion of the light is first split off by a second beam splitter 415 (425) and detected by a photodetector 416 (426) to monitor whether an eavesdropper will inject intense light for eavesdropping. The light pulse sequentially passes through the optical attenuator 414 (424), the phase modulator 413 (423), the intensity modulator 412 (422) and is then reflected by the faraday mirror 411 (421). The positions of the intensity modulator and the phase modulator can be interchanged here. The intensity of the light pulses after being reflected is adjusted by the intensity modulator 412 (422) per pulse for implementing a decoy scheme. The phase modulator 413 (423) is used to load phase information. The coding mode (X basis) and the decoy mode (Z basis) are performed randomly. When the encoding mode (X basis) is selected, the pulse intensity is adjusted by the intensity modulator 412 (422) so that 410 (420) the output intensity isα|2And encodes the random key by the phase modulator 413 (423). When the trick mode (Z-basis) is selected for execution, the intensity modulator is adjusted according to the trick mode protocol used and the random phase is encoded by the phase modulator. The encoded light pulses are returned to third party 430 for a pass through beamsplitter 431Order interference and measurement using single photon detectors 432 and 433.
The optical pulse signals used by the transmitters 410 and 420 for encoding in this embodiment originate from the same pulse (provided by the third party 430) and therefore have the same initial phase. But since the two sub-pulses experience different fibers after passing through the beam splitter 431, the phase change of the two may be different. Therefore, the sender can provide a phase reference by preparing a phase reference pulse for calibrating the phase change caused by the optical path change. The method of making the phase reference pulse is described with reference to fig. 3.
In the present embodiment, a plug and play structure is adopted, and the optical pulse reaches both Alice 410 and Bob 420 of the legitimate communication from the third party Charlie 430, is reflected by the faraday mirror, and then returns in the original path, and this structure can automatically perform polarization compensation. The photons have the same polarization state when they return to the beamsplitter 431 of the third party Charlie 430, thus ensuring high interference visibility.
Fourth embodiment: fig. 5 is a schematic diagram of an architecture of another embodiment of a measuring device-independent phase matching quantum key distribution apparatus.
The quantum key distribution system 500 shown in fig. 5 uses a strongly attenuated laser as communication light, and may include Alice 510 and Bob 520 of legitimate communication parties and an untrusted third party Charlie 530. The light source 534 emits pulsed light, which is transmitted to the communicating parties 510 and 520 through the beam splitter 531 after passing through the circulator 533. After reaching Alice 510 (Bob 520), the optical pulse signal is first sent to Bob 520 (Alice 510) after passing through the second circulators 517 (527) and 513 (523). The first circulator and the second circulator have the same function, and are not distinguished by the first circulator and the second circulator because reference numbers are provided in the figures. Through circulator 523 (513), reaches beam splitter 522 (512), and one path of optical signal is detected by photodetector 521 (511) to monitor whether an eavesdropper eavesdrops (the eavesdropper can extract encoded phase information by sending an intense light pulse and measuring the intense light pulse after being encoded by Alice 520 and Bob 510). The other optical pulse signal is subjected to loading of the spoofed state and the key information by the intensity modulators 524 (514) and the phase modulators 525 (515) in sequence. The encoded optical pulses are transmitted back to the third party 530 by attenuation. The third party performs first order interference through the beam splitter 531 after receiving the light pulse and measures the interference result using the single photon detectors 533 and 532.
In the present embodiment, a loop structure is adopted, and light pulses experience the same optical path between the transmission side 510 (520) and the third party 530 and between the transmission sides 510 and 520 except for the transmission side base stations 510 and 520. The structure can realize self-compensation of the phase as long as the optical path inside the base station is stable, so that additional phase reference does not need to be provided.
Different from the prior art, the invention provides a method for distributing measurement equipment irrelevant phase matching quantum keys, and the communication method and the communication system realize the coding and decoding of the keys by introducing phase reference without carrying out laser phase locking and phase post-selection, thereby greatly reducing the realization difficulty of experiments and improving the code rate; the problem that the phase is needed to be selected after the initial phases of the signal pulses are different is solved, and the code rate can be effectively improved.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.
Claims (8)
1. A measuring device-independent phase-matching quantum key distribution apparatus, comprising:
the first communication terminal and the second communication terminal which are legal and the third party detection terminal which is not trusted;
the first communication end and the second communication end are used for quantum state preparation and respectively comprise a phase modulator and an optical attenuator; the first communication end and the second communication end perform phase modulation on the signal pulse light through the phase modulator according to the executed quantum key distribution protocol, and the modulation mode of the phase modulator comprises a random switching coding mode and a decoy mode; the pulse light after phase modulation is attenuated to the appointed pulse intensity by an optical attenuator;
the third-party detection end is used for performing first-order interferometry and comprises a beam splitter, a first single photon measurer and a second single photon measurer; the first communication end and the second communication end send the prepared optical pulse signals to a third-party detection end, the first-order interference measurement is carried out by sending the optical pulse signals to the beam splitter, two optical pulses of the result are output, the two optical pulses are respectively received by the first single-photon detector and the second single-photon detector for measurement, and the measurement result is published;
the third-party detection end also comprises a relative phase measurement module which is respectively connected with the first optical switch and the second optical switch, optical pulse signals generated by the light sources of the first communication end and the second communication end comprise phase reference pulses and measurement signal pulses, the first optical switch and the second optical switch send the phase reference pulses to the relative phase measurement module for measurement, and simultaneously send the measurement signal pulses to the beam splitter for first-order interference;
the third party detection end is provided with a first optical switch and a second optical switch which respectively and correspondingly receive optical pulses transmitted by the first communication end and the second communication end; and a second phase modulator is arranged between the first optical switch and the beam splitter or between the second optical switch and the beam splitter and is used for carrying out phase compensation so as to eliminate the influence of the initial phase of the signal pulse.
2. The apparatus according to claim 1, wherein the phase modulators of the first and second communication terminals are respectively preceded by a light source for generating signal light pulses according to an implemented quantum key distribution protocol.
3. The quantum key distribution device with irrelevant phase matching for measuring equipment as claimed in claim 1, wherein the light sources of the first communication terminal and the second communication terminal are generated by a third party detection terminal, the light source of the third party detection terminal is connected with the beam splitter through a first circulator, and is divided into two beams through the beam splitter and respectively sent to the first communication terminal and the second communication terminal.
4. The quantum key distribution device with independent phase matching for measuring equipment of claim 3, wherein the optical attenuators of the first communication end and the second communication end are respectively connected with a second beam splitter, a part of light split by the second beam splitter respectively enters the phase modulator through the optical attenuators, and an intensity modulator is arranged behind the phase modulator;
the light pulse is emitted from the intensity modulator and reflected by the faraday mirror.
5. The apparatus for distributing unrelated phase matching quantum key of claim 4, wherein the second beam splitters of the first communication end and the second communication end are respectively connected to a photodetector, and another portion of light split by the second beam splitter is received for detection, so as to monitor whether an eavesdropper can inject strong light for eavesdropping.
6. The quantum key distribution device of claim 4, wherein when the phase modulator selects the encoding mode, the intensity of the pulse is adjusted by the intensity modulator so that the output intensities of the first communication terminal and the second communication terminal are adjusted, and the random key is encoded by the phase modulator; when the phase modulator selects to execute a decoy mode, the intensity modulator is adjusted according to the used decoy state protocol, a random phase is encoded through the phase modulator, the encoded light pulse is returned to a third-party detection end, first-order interference is carried out through the beam splitter, and measurement is carried out through the first single-photon detector and the second single-photon detector.
7. The quantum key distribution device with irrelevant phase matching for measuring equipment as claimed in claim 3, wherein the beam splitter is divided into two beams which are respectively sent to the first communication end and the second communication end, a second circulator and a third circulator are respectively arranged in the first communication end and the second communication end, the optical pulse is sent to the second beam splitter through the second circulator and the third circulator in the first communication end and the second communication end, the second beam splitter is connected with the intensity modulator, and a part of light formed by beam splitting of the beam splitter respectively enters the intensity modulator, the phase modulator and the optical attenuator to carry out loading of decoy state and key information; and then the first-order interference is carried out in a beam splitter at a third-party detection end, the output result is received by the first single-photon detector and the second single-photon detector for measurement, and the measurement result is published.
8. The apparatus according to claim 7, wherein the second beam splitters of the first and second communication terminals are respectively connected to a photodetector, and another portion of the split light is detected by the photodetector to monitor whether an eavesdropper can inject strong light for eavesdropping.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811506414.6A CN109379188B (en) | 2018-12-10 | 2018-12-10 | Measuring equipment irrelevant phase matching quantum key distribution device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811506414.6A CN109379188B (en) | 2018-12-10 | 2018-12-10 | Measuring equipment irrelevant phase matching quantum key distribution device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109379188A CN109379188A (en) | 2019-02-22 |
| CN109379188B true CN109379188B (en) | 2022-03-15 |
Family
ID=65373181
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811506414.6A Active CN109379188B (en) | 2018-12-10 | 2018-12-10 | Measuring equipment irrelevant phase matching quantum key distribution device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109379188B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111030756A (en) * | 2019-12-17 | 2020-04-17 | 中国人民解放军国防科技大学 | Measuring equipment irrelevant quantum key distribution system based on logic coding and method thereof |
| CN111294206B (en) * | 2020-04-28 | 2020-07-28 | 南京大学 | Quantum conference key negotiation method and system |
| CN116076035A (en) * | 2020-07-14 | 2023-05-05 | 新加坡国立大学 | Method and system for a measurement device independent quantum key distribution network |
| CN112491542A (en) * | 2020-11-16 | 2021-03-12 | 南京大学 | Local oscillator four-state continuous variable quantum key distribution method and system |
| CN112929160B (en) * | 2021-01-22 | 2022-03-04 | 西安电子科技大学 | Plug-and-play reference system and measuring equipment independent quantum key distribution system and method |
| CN112929161B (en) * | 2021-01-22 | 2022-01-07 | 西安电子科技大学 | Plug-and-play type reference system-independent double-field quantum key distribution protocol implementation method |
| CN116192366A (en) * | 2021-11-29 | 2023-05-30 | 科大国盾量子技术股份有限公司 | TF-QKD system and method |
| CN114285548B (en) * | 2021-12-03 | 2024-03-15 | 济南量子技术研究院 | Decoy MDI-QKD method and system based on phase post-selection |
| CN114337847B (en) * | 2021-12-31 | 2023-07-18 | 山西大学 | Continuous variable measurement device independent quantum key distribution system and phase compensation method |
| CN114900412A (en) * | 2022-05-09 | 2022-08-12 | 济南量子技术研究院 | Single-SPD-based QKD system public phase difference estimation method and system |
| CN116488805B (en) * | 2023-04-28 | 2024-01-23 | 正则量子(北京)技术有限公司 | Quantum key distribution method and system, quantum measurement method and device |
| CN117879818B (en) * | 2024-03-12 | 2024-05-10 | 正则量子(北京)技术有限公司 | Quantum key distribution method and device based on mode pairing |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106685658A (en) * | 2017-03-20 | 2017-05-17 | 中国人民解放军空军工程大学 | Quantum key distribution system and method based on continuous variable measurement equipment independence |
| CN206364813U (en) * | 2017-01-16 | 2017-07-28 | 浙江神州量子网络科技有限公司 | A kind of measuring apparatus unrelated quantum key distribution system of PP structures |
| CN107171793A (en) * | 2017-06-05 | 2017-09-15 | 浙江神州量子网络科技有限公司 | From the unrelated CV QKD systems of the measuring apparatus of steady phase and method |
-
2018
- 2018-12-10 CN CN201811506414.6A patent/CN109379188B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN206364813U (en) * | 2017-01-16 | 2017-07-28 | 浙江神州量子网络科技有限公司 | A kind of measuring apparatus unrelated quantum key distribution system of PP structures |
| CN106685658A (en) * | 2017-03-20 | 2017-05-17 | 中国人民解放军空军工程大学 | Quantum key distribution system and method based on continuous variable measurement equipment independence |
| CN107171793A (en) * | 2017-06-05 | 2017-09-15 | 浙江神州量子网络科技有限公司 | From the unrelated CV QKD systems of the measuring apparatus of steady phase and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109379188A (en) | 2019-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109379188B (en) | Measuring equipment irrelevant phase matching quantum key distribution device | |
| JP6602410B2 (en) | Photon communication system | |
| Wang et al. | Beating the fundamental rate-distance limit in a proof-of-principle quantum key distribution system | |
| JP6760976B2 (en) | Chip-based quantum key distribution | |
| Da Silva et al. | Proof-of-principle demonstration of measurement-device-independent quantum key distribution using polarization qubits | |
| CN106656344B (en) | MDI-QKD system and MDI-QKD method | |
| GB2551685A (en) | An optical device, a transmitter for a quantum communication system and a quantum communication system | |
| US8098826B2 (en) | QKD system laser autocalibration based on bit-error rate | |
| CN110190905B (en) | Transmitting terminal of time phase quantum key distribution system | |
| CN210839602U (en) | Quantum key transmitter and quantum key distribution system | |
| Shao et al. | Phase noise model for continuous-variable quantum key distribution using a local local oscillator | |
| CN210839583U (en) | Time phase encoding device, quantum key transmitter and quantum key distribution system | |
| CN112887090A (en) | Continuous variable four-state quantum key distribution method and system | |
| CN210839599U (en) | Quantum key transmitter and quantum key distribution system | |
| KR102225679B1 (en) | Time Division Quadrature Homodyne CV QKD system | |
| CN110351075B (en) | Continuous variable quantum key distribution system | |
| JP4962700B2 (en) | Quantum cryptographic communication device | |
| JP7176070B2 (en) | Optical system and method | |
| Shakhovoy et al. | Wavelength-and Time-Division Multiplexing via Pump Current Variation of a Pulsed Semiconductor Laser—A Method of Synchronization for Quantum Key Distribution | |
| CN113992323B (en) | Chip-based measuring equipment independent quantum key distribution system and method | |
| US20220085895A1 (en) | Generation of optical pulses with controlled distributions of quadrature values | |
| JP2022182988A (en) | Emitter, communication system, and method | |
| JP2007266738A (en) | Quantum cryptographic communication apparatus and communication terminal | |
| CN113632414A (en) | Light injection locking in quantum key distribution | |
| US11736198B2 (en) | Optical emitter, communication system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |