CN114553402A - Sagnac loop-based reference system-independent measurement device-independent QKD system and method - Google Patents
Sagnac loop-based reference system-independent measurement device-independent QKD system and method Download PDFInfo
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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
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Abstract
The invention discloses a system and a method for QKD independent of a reference system independent measuring device based on a sagnac loop, comprising a transmitting end Alice, a transmitting end Bob and a measuring end Charlie; the transmitting end Alice, the transmitting end Bob and the measuring end Charlie are connected through a free space channel; the transmitting end Alice comprises a Laser1 and a first sagnac loop modulator, wherein the first sagnac loop modulator comprises an intensity modulator IM1, a polarization controller PC1, an optical circulator Cir1, a first transmitting end sagnac loop, an optical attenuator ATT1 and a fiber collimator Col 1; the transmitting end Bob comprises a Laser2 and a second sagnac loop modulator, wherein the second sagnac loop modulator comprises an intensity modulator IM2, a polarization controller PC2, an optical circulator Cir2, a second transmitting end sagnac loop, an optical attenuator ATT2 and a fiber collimator Col 2; the invention solves the problem of complex preparation of the intermediate state in the prior art, has higher speed and better stability, achieves the purposes of eliminating the influence of the environment on the polarization state, does not need to align a reference system, simplifies the complexity of the system and improves the code rate.
Description
Technical Field
The invention belongs to the technical field of quantum information and optical communication, and particularly relates to a sagnac loop-based QKD system and method independent of a reference system independent measuring device.
Background
The quantum key distribution technology is based on the basic principle of quantum mechanics, and theoretically proves that unconditional and safe key sharing can be realized. However, due to the non-ideal characteristics of actual devices and equipment, the actual security of the quantum key distribution system is different from the theoretical security, wherein the single photon detector in the detection end is the most vulnerable part, and the actual security of the quantum key distribution system is seriously affected.
The measuring equipment Independent Quantum Key Distribution protocol (MDI QKD) perfectly solves the security problem caused by the nonideality of measuring end equipment by utilizing Bell state projection Measurement. In the measuring equipment irrelevant quantum key distribution protocol, both Alice and Bob of legal communication parties are senders, and the legal communication parties send the prepared quantum state to an untrusted third party Charlie to perform Bell state projection measurement to obtain a projected Bell state, wherein the safety of the projected Bell state is irrelevant to the third party.
The prior art patents are as follows: (CN108199768A) proposes a measuring device independent protocol using W state, which can completely eliminate the potential safety hazard of the detector. However, the W-state preparation adopted by the method is relatively complex, has higher technical requirements and is difficult to realize perfectly.
The prior art patents are as follows: (CN108183793A) proposes a measuring device independent protocol for modulating polarization state by using a polarization controller, and the adopted structure is simple, and the required detectors and optical elements are fewer, the loss is small, and the cost is low. But the speed of modulating the polarization state by using the polarization controller is slower, and the stability is poorer.
The prior art patents are as follows: (CN107332627A) provides a method for disturbing the polarization state of an optical pulse signal or an optical quantum signal by a quantum state preparation sending end, so that the polarization state of the optical pulse signal or the optical quantum signal is uniformly distributed on the surface of a poincare sphere to reduce the influence of the environment on the polarization state. But the method used by the method has the disadvantages of complex operation, complex structure and higher cost.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a Sagnac loop-based reference system independent measurement device independent QKD system. In addition, the Sagnac ring modulator adopts the phase modulator to modulate polarization, so that the speed is higher and the stability is better; meanwhile, the invention better utilizes the relevant properties of the Q-plate of the Q plate, achieves the purposes of eliminating the influence of the environment on the polarization state, does not need to align the reference system and improves the code rate. And the operation is easy and the structure is simple.
In order to achieve the purpose, the invention adopts the following technical scheme: a QKD system irrelevant to measuring equipment is irrelevant to a reference system based on a sagnac loop, and comprises a transmitting end Alice, a transmitting end Bob and a measuring end Charlie; the transmitting end Alice, the transmitting end Bob and the measuring end Charlie are connected through a free space channel;
the transmitting end Alice comprises a Laser1 and a first sagnac loop modulator which are connected with each other, wherein the first sagnac loop modulator comprises an intensity modulator IM1, a polarization controller PC1, an optical circulator Cir1, a first transmitting end sagnac loop, an optical attenuator ATT1, a fiber collimator Col1 and a Q-plate 1;
the Laser1 is used for generating a first optical pulse which is used as a quantum signal for systematic encoding to generate a key;
the intensity modulator IM1 is used for intensity modulating the first light pulse;
the polarization controller PC1 is used for changing the quantum signal into 45-degree linearly polarized light;
the Q-plate1 is used for coupling the spin angular momentum with the orbit angular momentum;
the transmitting end Bob comprises a Laser2 and a second sagnac loop modulator which are connected with each other, and the second sagnac loop modulator comprises an intensity modulator IM2, a polarization controller PC2, an optical circulator Cir2, a second transmitting end sagnac loop, an optical attenuator ATT2, a fiber collimator Col2 and a Q-plate 4;
the Laser2 is used for generating a second optical pulse which is used as a quantum signal for systematic encoding to generate a key;
the intensity modulator IM2 is used for single modulation of the second light pulse;
the polarization controller PC2 is used for changing the quantum optical signal into 45-degree linearly polarized light;
the Q-plate4 is used for coupling the spin angular momentum with the orbit angular momentum;
the measurement end Charlie comprises reflectors Mirror 1-Mirror 14, Q plates Q-plate2, Q plates Q-plate3 and a BSM measuring instrument, wherein the BSM measuring instrument comprises a beam splitter BS, a polarization beam splitter PBS and a single photon detector D1HSingle photon detector D1VSingle photon detector D2HAnd a single photon detector D2V(ii) a The beam splitter BS is connected with the polarizing beam splitter PBS3 and a polarizing beam splitter PBS 4; the single photon detector D1HAnd a single photon detector D1VIs connected with the polarizing beam splitter PBS 3; the single photon detector D2HAnd a single photon detector D2VConnected with a polarizing beam splitter PBS 4;
the first transmitting end sagnac loop is used for dividing 45-degree linearly polarized light into first horizontal polarized light and first vertical polarized light, converging the first horizontal polarized light and the first vertical polarized light, emitting the light to an optical attenuator ATT1 through an optical circulator Cir1, attenuating the light to set light intensity through an optical attenuator ATT1, converting a signal into a space optical signal through an optical fiber collimator Col1, coupling the space optical signal with a Q plate, and transmitting the space optical signal to a measuring end Charlie through a free space channel;
the second transmitting end sagnac loop is used for dividing 45-degree linearly polarized light into second horizontal polarized light and second vertical polarized light, merging the second horizontal polarized light and the second vertical polarized light, emitting the merged light to an optical attenuator ATT2 through an optical circulator Cir2 after being merged by PBS2, attenuating the merged light to set light intensity through an optical attenuator ATT2, converting the signal into a space optical signal through an optical fiber collimator Col1, coupling the space optical signal with a Q plate Q-plate1, and transmitting the space optical signal to a measuring end Charlie through a free space channel;
after the first optical pulse and the second optical pulse reach a measurement end Charlie, the first optical pulse and the second optical pulse are respectively reflected to a Q plate Q-plate2 and a Q plate Q-plate3 by a reflector Mirror1 and a Mirror3, demodulated by a Q plate Q-plate2 and a Q plate Q-plate3, respectively reflected to an optical fiber collimator Col3 and a Col4 by a transmitting Mirror Mirror2 and a Mirror4, and coupled into an optical fiber by an optical fiber collimator Col3 and Col4, and transmitted to a BSM measuring instrument for Bell state measurement.
Preferably, the first transmitting end sagnac loop includes a polarization beam splitter PBS1, a variable optical attenuator VOA1, a phase modulator PMA and an optical rotator 1; the polarization beam splitter PBS1, the variable optical attenuator VOA1, the phase modulator PMA and the optical rotator1 are connected in series by adopting polarization-maintaining optical fibers in sequence;
the polarizing beam splitter PBS1 is used for splitting 45-degree linearly polarized light into first horizontally polarized light and first vertically polarized light;
the phase modulator PMA is used for modulating the phase of polarized light in a clockwise or counterclockwise direction;
the light rotator1 is used for rotating the horizontal polarized light propagating clockwise by 90 ° to the vertical polarized light and rotating the vertical polarized light propagating counterclockwise by 90 ° to the horizontal polarized light;
the first horizontal polarized light and the first vertical polarized light are respectively transmitted in the polarization-maintaining optical fiber clockwise and anticlockwise; the first horizontally polarized light sequentially passes through the variable optical attenuator VOA1, the phase modulator PMA and the optical rotator1 to reach the polarization beam splitter PBS1, and the first vertically polarized light sequentially passes through the optical rotator1, the phase modulator PMA and the variable optical attenuator VOA1 to reach the polarization beam splitter PBS1 and is merged with the first horizontally polarized light reaching the polarization beam splitter PBS 1.
Preferably, the phase modulator PMA is placed at one end close to the vertical polarized light outlet of the polarization beam splitter PBS1, so that the first horizontal polarized light and the second vertical polarized light reach the phase modulator PMA with a time difference, which is used for modulating the phase of the required clockwise and counterclockwise propagating polarized light only in the clockwise or counterclockwise direction; when the phase modulator PMA loads the first vertically polarized light with a phase of 0, then output from the polarizing beam splitter PBS1 is | + >, representing bit 1; when the phase modulator PMA loads the first vertically polarized light by pi/2, then output from the polarizing beam splitter PBS1 is, | - >, representing bit 0.
Preferably, the second transmitting end sagnac loop includes a polarization beam splitter PBS2, a variable optical attenuator VOA2, a phase modulator PMB, and an optical rotator 2;
the polarization beam splitter PBS2, the variable optical attenuator VOA2, the phase modulator PMB and the optical rotator2 are connected in series by polarization-maintaining optical fibers in sequence;
the polarization beam splitter PBS2 splits the 45-degree linearly polarized light into a second horizontally polarized light and a second vertically polarized light;
the phase modulator PMB is used for modulating the phase of polarized light in a clockwise direction or a counterclockwise direction;
a light rotator2 for rotating the clockwise propagating horizontally polarized light by 90 ° to vertically polarized light and the counterclockwise propagating vertically polarized light by 90 ° to horizontally polarized light;
the second horizontally polarized light and the second vertically polarized light are respectively transmitted in the polarization maintaining optical fiber clockwise and counterclockwise, the second horizontally polarized light sequentially passes through the variable optical attenuator VOA2, the phase modulator PMB and the optical rotator2 to reach the polarization beam splitter PBS2, and the second vertically polarized light sequentially passes through the optical rotator2, the phase modulator PMB and the variable optical attenuator VOA2 to reach the polarization beam splitter PBS 2.
Preferably, the phase modulator PMB is placed at an end close to the vertical polarized light outlet of the polarization beam splitter PBS2, so that the second horizontal polarized light and the second vertical polarized light reach the phase modulator PMB with a time difference, and the time difference is that the polarization light which needs to be transmitted clockwise and counterclockwise for modulating the phase modulates the phase only in the clockwise or counterclockwise direction; when phase modulator PMB loads the vertically polarized light with a phase of 0, then output from polarizing beam splitter PBS2 is | + >, representing bit 1; when the phase modulator PMB loads the vertically polarized light by pi/2, then output from polarizing beamsplitter PBS2 is, | - >, representing bit 0.
Preferably, the polarization state of the light pulse of the clockwise-propagating first and second horizontally polarized light is | H>Become by adjusting the phase modulator
The polarization state of the light pulse of the first vertically polarized light and the second vertically polarized light propagating counterclockwise is | V>By adjusting the phase modulators PMA and PMB may be changed to
The quantum state of the light pulse when the vertically polarized light and the horizontally polarized light were combined at polarizing beam splitter PBS1 was
Preferably, the Q-plate1 and Q-plate4 will have a polarization state | H>Into a quantum state
Changing the polarization state | V > into a quantum state
Will polarize the state | +>Conversion into quantum state
Polarization state | ->Conversion to a quantum state
Wherein R>Represents a right-handed circularly polarized state, | L>Represents a left-hand circular polarization state, | l ═ 1>Represents a state with an orbital angular momentum topological charge value of 1, | 1 ═ 1>Representing a state with an orbital angular momentum topological charge value of-1.
Preferably, the Q-plate2 and Q-plate3 convert quantum states
Is converted back to polarization state | H>Will be
Is converted back to the polarization state | V>Quantum state of the quantum
Is converted back to polarization state | +>Quantum state of the quantum
Polarization state of polarization | ->。
Preferably, the BSM measuring instrument can only measure the polarization state | ψ generated after the two signals are combined by the beam splitter BS+Phi and phi-When the polarization state of the light pulse is measured to be | ψ+Time, single photon detector D1HAnd D1VOr D2HAnd D2VIn response, when the polarization state of the light pulse is measured as | ψ-Time, single photon detector D1HAnd D2VOr D2HAnd D1VAnd respond at the same time.
The invention also provides a sagnac loop-based reference system-independent measurement device-independent QKD method, which is applied to a sagnac loop-based reference system-independent measurement device-independent QKD system as described in any one of the above items, and is characterized in that the method comprises the following steps:
s1, a transmitting end Alice and a transmitting end Bob serve as two communication parties to simultaneously send quantum signals, polarization information is loaded by loading phases through a sagnac loop, when a phase modulator does not modulate and a variable optical attenuator VOA blocks a counterclockwise pulse, a polarization state | H > is loaded, when the phase modulator does not modulate and the VOA blocks a clockwise pulse, a polarization state | V > is loaded, when the phase modulator modulates horizontal polarization light by 0 degree and the variable optical attenuator VOA does not modulate, a polarization state | plus is loaded, when the phase modulator modulates horizontal polarization light by pi, a polarization state | is loaded, and the polarization state | is then coupled through a Q plate and sent to a measuring end Charlie through a free space channel.
S2 two pathsQuantum signals reach a measurement end Charlie, polarization and orbital angular momentum are decoupled through two Q plates, then the quantum signals enter a BSM measuring instrument for measurement, and when the polarization state of optical pulses is measured to be | psi+Time, single photon detector D1HAnd D1VOr D2HAnd D2VIn response, when the polarization state of the light pulse is measured as | ψ-When more than the first time, single photon detector D1HAnd D2VOr D2HAnd D1VResponding at the same time;
s3, the measurement end Charlie publishes the measurement result of the BSM measuring instrument through a classical channel, and the two communication parties obtain the detection result from the measurement end Charlie;
s4, the transmitting end Alice publishes the base selection condition through a classical channel, and the transmitting end Bob omits a detection result different from the base selection condition of the transmitting end Alice to obtain an original secret key;
s5, the transmitting terminal Bob selects part of the keys to carry out error code detection; if the error rate exceeds the set threshold, the existence of an eavesdropper is proved, the result is discarded, and the process is restarted; if the error rate does not exceed the set threshold, continuing the next operation;
s6, post-processing the original key to obtain a usable security key.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention preferably provides an irrelevant protocol for measuring equipment by utilizing the polarization state generated by the Sagnac ring modulator, has simple operation and easy realization, and solves the problem of more complex preparation of the state in the prior art.
2. The Sagnac ring modulator provided by the invention modulates polarization by adopting the phase modulator, so that the speed is higher and the stability is better.
3. The invention better utilizes the relevant properties of the Q-plate, achieves the purposes of eliminating the influence of the environment on the polarization state, does not need to align the reference system, simplifies the complexity of the system, improves the code rate, and has easy operation and simple structure.
4. The invention utilizes the thought irrelevant to the measuring equipment, avoids all attacks aiming at the measuring end, and has good stability and low cost.
Drawings
FIG. 1 is a schematic diagram of the structural principles of a sagnac loop-based reference frame independent measurement device independent QKD system of the present invention;
FIG. 2 is a schematic diagram of a BSM meter of a Sagnac-loop-based reference-system-independent QKD system;
FIG. 3 is a block diagram of a first sagnac loop modulator of a sagnac loop-based, reference frame-independent, measurement device-independent QKD system of the present invention;
FIG. 4 is a block diagram of a second sagnac loop modulator of a sagnac loop-based, reference frame-independent, measurement device-independent QKD system of the present invention;
FIG. 5 is a flow chart of a sagnac loop-based reference frame independent measurement device independent QKD method of the present invention;
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the following embodiments.
Example 1
As shown in fig. 1 to 4, the invention provides a sagnac loop-based reference frame-independent measurement device-independent QKD system, which includes a transmitting end Alice, a transmitting end Bob and a measuring end Charile; the transmitting end Alice and the transmitting end Bob are connected with the measuring end Chairle through a free space channel (the free space channel is air); the transmitting end Alice and the transmitting end Bob have the same structure, and the transmitting end Alice is taken as an example to describe the signal transmission process of the present invention.
The transmitting end Alice comprises a Laser1 and a first sagnac loop modulator which are connected with each other, wherein the first sagnac loop modulator comprises an intensity modulator IM1, a polarization controller PC1, an optical circulator Cir1, a first transmitting end sagnac loop, an optical attenuator ATT1, a fiber collimator Col1 and a Q-plate 1;
the transmitting end sagnac loop comprises a polarization beam splitter PBS1, a variable optical attenuator VOA1, a phase modulator PMA and an optical rotator 1; the polarization beam splitter PBS1, the variable optical attenuator VOA1, the phase modulator PMA and the optical rotator1 are connected in series by adopting polarization-maintaining optical fibers in sequence.
The Laser1 is used to produce optical pulses that are used as quantum signals for systematic encoding to generate keys. The intensity modulator IM1 is used for intensity modulating the first light pulse; the polarization controller PC1 is used for changing the quantum optical signal into 45-degree linearly polarized light; the Q-plate1 is used for coupling the spin angular momentum with the orbit angular momentum;
the optical circulator Cir1 is an optical device that irreversibly polarizes an optical signal based on the faraday effect. The optical circulator is divided into three ports, and light can only propagate along one direction. Port 1 is an input port and port 2 is an output port, and a reflected signal reflected back to port 2 will be redirected to port 3 instead of port 1, the order of the ports being labeled clockwise from bottom to top in the direction of the arrows in the figure.
The polarizing beam splitter PBS1 split the 45 ° linearly polarized light, and the polarizing beam splitter PBS1 split the 45 ° linearly polarized light into horizontally polarized light and vertically polarized light.
The light rotator1 is used for rotating the horizontal polarized light propagating clockwise by 90 ° to the vertical polarized light and rotating the vertical polarized light propagating counterclockwise by 90 ° to the horizontal polarized light;
the phase modulator PMA is used for modulating the phase of polarized light in a clockwise or counterclockwise direction; the phase modulator PMA is placed at one end near the exit of the vertical polarized light of the polarization splitting PBS1, so that the horizontally polarized light and the vertically polarized light reach the phase modulator PMA with a time difference, which is the required phase difference for modulating the phase, for the clockwise and counterclockwise propagating polarized light only modulates the phase in the clockwise or counterclockwise direction, and may not modulate in the other direction.
The horizontal polarized light and the vertical polarized light are respectively transmitted in the polarization maintaining optical fiber along the clockwise direction and the anticlockwise direction; the horizontally polarized light sequentially passes through the variable optical attenuator VOA1, the phase modulator PMA and the optical rotator1 to reach the polarization beam splitter PBS 1; the vertically polarized light passes through the optical rotator1, the phase modulator PMA, and the variable optical attenuator VOA1 in this order to reach the polarization beam splitter PBS 1.
When reaching the variable optical attenuator VOA1, the horizontally polarized light and the vertically polarized light can be adjusted according to the requirements of the preparation bases, and the specific adjustment mode and results are shown in the following table 1;
TABLE 1
The horizontally polarized light and the vertically polarized light are converged by the PBS1, then are emitted to the optical attenuator ATT1 through the optical circulator Cir1 and are attenuated to set light intensity by the optical attenuator ATT1, then the signals are converted into space optical signals through the optical fiber collimator Col1, the space optical signals are coupled with the Q-plate1, and the space optical signals are transmitted to the measurement end Charlie through a free space channel.
Similarly, the transmitting end Bob transmits the space optical signal to the third party measuring end Charlie through the free space channel;
the measurement end Charlie comprises reflectors Mirror 1-Mirror 14, Q plates Q-plate2, Q plates Q-plate3 and a BSM measuring instrument, wherein the BSM measuring instrument comprises a beam splitter BS, a polarization beam splitter PBS and a single photon detector D1H(ii) a Single photon detector D1VSingle photon detector D2HAnd a single photon detector D2V(ii) a The beam splitter BS is connected with the polarizing beam splitter PBS3 and a polarizing beam splitter PBS 4; the single photon detector D1HAnd a single photon detector D1VIs connected with the polarizing beam splitter PBS 3; the single photon detector D2HAnd a single photon detector D2VConnected with a polarizing beam splitter PBS 4;
after the light pulses at the Alice end and the Bob end of the emitting end reach the measuring end Charlie, the two light pulses are respectively reflected to a Q-plate2 and a Q-plate3 by a reflector Mirror1 and a Mirror3, and are respectively reflected to optical fiber collimators Col3 and Col4 by a reflector Mirror2 and a Mirror4 after being demodulated by a Q Q plate Q-plate2 and a Q-plate3 and are coupled into the optical fibers by the optical fiber collimators Col3 and Col 4. As shown in fig. 2, two signals are transmitted to the BSM measuring instrument for Bell-state measurement, and each single photon detector has different responses according to the measurement result.
In the invention, the set light intensity is single photon light intensity, the quantum state of the light pulse of the horizontal polarized light which propagates clockwise is | H >, and the quantum state is changed into the quantum state after the phase modulator PMA is adjusted
The quantum state of a counterclockwise propagating optical pulse of vertically polarized light is | V>By adjusting the quantum state of the phase modulator PMA to become
The quantum states of the light pulses when vertically polarized light and horizontally polarized light were at polarizing beam splitter PBS1 were
In the invention, the phase modulator only modulates vertical polarized light to generate | + > and | - >, and the modulated optical attenuator ATT1 generates | H > and | V >, namely X base and Z base are obtained.
As shown in fig. 1, two emitting ends Alice and Bob have the same structure, taking the emitting end Alice as an example, after the Laser1 generates pulsed light, the pulsed light is changed into 45 ° linearly polarized light through the action of the polarization controller PC1, and the 45 ° linearly polarized light passes through the optical circulator Cir1 and is incident into the polarization beam splitter PBS1, at this time, the polarization beam splitter PBS1 splits the linearly polarized light into horizontal polarized light and vertical polarized light, the two beams of light propagate in sagnac along the clockwise direction and the counterclockwise direction respectively, and at this time, the purpose of loading the phase of only the vertical polarized light is achieved by calculating the time when the vertical polarized light and the horizontal polarized light reach the phase modulator PMA. When the phase modulator PMA loads the phase of 0 to the vertically polarized light, the output from the polarization beam splitter at this time is | +>Represents bit 1; when the phase is adjustedWhen the PMA loads the vertical polarized light by pi/2, the output from the polarization beam splitter is | ->Representing bit 0; when the phase modulator PMA is not modulated and the variable optical attenuator VOA is modulated, respectively, | H can be generated>And | V>The polarization state. Representing bit 1 and bit 0, respectively, all of the base information required for polarization BB84 is now generated. The Q-plate1 may implement the polarization state | H>Into a quantum state
Will polarize the state | V>Into a quantum state
Polarization state | +>Conversion into quantum state
Polarization state | ->Conversion to a quantum state
Wherein R>Represents a right-handed circularly polarized state, | L>Represents a left-hand circular polarization state, | l ═ 1>Represents a state with an orbital angular momentum topological charge value of 1, | 1 ═ 1>Representing a state with an orbital angular momentum topological charge value of-1.
The Q plate Q-plate2 can realize quantum state conversion
Is converted back to the polarization state | H >, will
Conversion to polarization state | V >, quantum state
Conversion to polarization state | + >, quantum state
Polarization state of polarization | ->. At the measurement end Charlie, i.e. the conventional BB84 measurement device independent protocol, the satisfied relationship is as shown in table 1 above:
the BSM measuring instrument can only measure the polarization state | psi generated by the combination of two paths of signals through the beam splitter BS+>And | ψ->When the polarization state of the optical pulse is measured to be | ψ+>Time, single photon detector D1HAnd D1VOr D2HAnd D2VIn response, when the polarization state of the light pulse is measured as | ψ-Time, single photon detector D1HAnd D2VOr D2HAnd D1VAnd respond at the same time. Wherein | H>And | V>Is Z radical, | +>And | ->And when the two communication parties simultaneously select one of the X base or the Z base, the code can be formed according to the response results of different single-photon detectors by the Bell state measurement of the Charlie at the measuring end. The corresponding relationship between the detection result and the code forming result is shown in the following table 2:
TABLE 2
| Alice&Bob | Measure | psi+＞ | Measure | psi-＞ |
| Radical X | No bit flipping | Bit flipping |
| Z radical | Bit flipping | Bit flipping |
As shown in fig. 5, the present invention further provides a sagnac loop-based reference system-independent measurement device-independent QKD method, which is applied to a sagnac loop-based reference system-independent measurement device-independent QKD system as described in any of the above items, and is characterized in that: the method comprises the following steps:
s1, an emitting end Alice and an emitting end Bob serve as two communication parties to simultaneously send quantum signals, polarization information is loaded by loading phases through a sagnac loop, when a phase modulator does not modulate and a variable optical attenuator VOA blocks a counterclockwise pulse, a polarization state | H > is loaded, when the phase modulator does not modulate and the VOA blocks a clockwise pulse, a polarization state | V > is loaded, when the phase modulator modulates 0 degree of horizontal polarization light and the variable optical attenuator VOA does not modulate, the polarization state | plus is loaded, when the phase modulator modulates pi of the horizontal polarization light, the polarization state | is loaded, and the polarization state | minus is loaded, is coupled through a Q plate and then is sent to a measuring end Charlie through a free space channel.
S2, enabling two paths of quantum signals to reach a measuring end Charlie, decoupling polarization and orbital angular momentum through two Q plates, and then entering a BSM measuring instrument for measurement, wherein when the polarization state of optical pulses is measured to be | psi+>Time, single photon detector D1HAnd D1VOr D2HAnd D2VIn response, when the polarization state of the light pulse is measured as | ψ->Time, single photon detector D1HAnd D2VOr D2HAnd D1VResponding at the same time;
s3, the measurement end Charlie publishes the measurement result of the BSM measuring instrument through a classical channel, namely the response condition of the single-photon detector, and the two communication parties obtain the detection result from the measurement end Charlie;
s4, the transmitting end Alice publishes the base selection condition through a classical channel, and the transmitting end Bob omits a detection result different from the base selection condition of the transmitting end Alice to obtain an original secret key;
s5, the transmitting terminal Bob selects part of the keys to carry out error code detection; if the error rate exceeds the set threshold, the existence of an eavesdropper is proved, the result is discarded, and the process is restarted; if the error rate does not exceed the set threshold, continuing the next operation;
s6, post-processing the original key to obtain a usable security key.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention preferably provides an irrelevant protocol for measuring equipment by utilizing the polarization state generated by the Sagnac ring modulator, has simple operation and easy realization, and solves the problem of more complex preparation of the state in the prior art.
2. The Sagnac ring modulator provided by the invention modulates polarization by adopting the phase modulator, so that the speed is higher and the stability is better.
3. The invention better utilizes the relevant properties of the Q-plate, achieves the purposes of eliminating the influence of the environment on the polarization state, does not need to carry out reference system alignment, simplifies the complexity of the system and improves the code rate. And the operation is easy and the structure is simple.
4. The invention utilizes the thought irrelevant to the measuring equipment, avoids all attacks aiming at the measuring end, and has good stability and low cost.
Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (10)
1. A QKD system irrelevant to measuring equipment based on a reference system of a sagnac loop comprises a transmitting end Alice, a transmitting end Bob and a measuring end Charlie; the transmitting end Alice, the transmitting end Bob and the measuring end Charlie are connected through a free space channel; the method is characterized in that:
the transmitting end Alice comprises a Laser1 and a first sagnac loop modulator which are connected with each other, wherein the first sagnac loop modulator comprises an intensity modulator IM1, a polarization controller PC1, an optical circulator Cir1, a first transmitting end sagnac loop, an optical attenuator ATT1, a fiber collimator Col1 and a Q-plate 1;
the Laser1 is used for generating a first optical pulse which is used as a quantum signal for systematic encoding to generate a key;
the intensity modulator IM1 is used for intensity modulating the first light pulse;
the polarization controller PC1 is used for changing the quantum signal into 45-degree linearly polarized light;
the Q-plate1 is used for coupling the spin angular momentum with the orbit angular momentum;
the transmitting end Bob comprises a Laser2 and a second sagnac loop modulator which are connected with each other, and the second sagnac loop modulator comprises an intensity modulator IM2, a polarization controller PC2, an optical circulator Cir2, a second transmitting end sagnac loop, an optical attenuator ATT2, a fiber collimator Col2 and a Q-plate 4;
the Laser2 is used for generating a second optical pulse which is used as a quantum signal for systematic encoding to generate a key;
the intensity modulator IM2 is used for single modulation of the second light pulse;
the polarization controller PC2 is used for changing the quantum optical signal into 45-degree linearly polarized light;
the Q-plate4 is used for coupling the spin angular momentum with the orbit angular momentum;
the measurement end Charlie comprises reflectors Mirror 1-Mirror 14, Q plates Q-plate2, Q plates Q-plate3 and a BSM measuring instrument, wherein the BSM measuring instrument comprises a beam splitter BS, a polarization beam splitter PBS and a single photon detector D1HSingle photon detector D1VSingle photon detector D2HAnd a single photon detector D2V(ii) a The beam splitter BS is connected with the polarizing beam splitter PBS3 and a polarizing beam splitter PBS 4; the single photon detector D1HAnd a single photon detector D1VIs connected with the polarizing beam splitter PBS 3; the single photon detector D2HAnd a single photon detector D2VConnected with a polarizing beam splitter PBS 4;
the first transmitting end sagnac loop is used for dividing 45-degree linearly polarized light into first horizontal polarized light and first vertical polarized light, converging the first horizontal polarized light and the first vertical polarized light, emitting the light to an optical attenuator ATT1 through an optical circulator Cir1, attenuating the light to set light intensity through an optical attenuator ATT1, converting a signal into a space optical signal through an optical fiber collimator Col1, coupling the space optical signal with a Q plate, and transmitting the space optical signal to a measuring end Charlie through a free space channel;
the second transmitting end sagnac ring is used for dividing 45-degree linearly polarized light into second horizontal polarized light and second vertical polarized light, converging the second horizontal polarized light and the second vertical polarized light, emitting the light to an optical attenuator ATT2 through an optical circulator Cir2 after being converged by PBS2, attenuating the light to set light intensity through an optical attenuator ATT2, converting the signal into a space optical signal through an optical fiber collimator Col1, coupling the space optical signal with a Q plate Q-plate1, and transmitting the space optical signal to a measuring end Charlie through a free space channel;
after the first optical pulse and the second optical pulse reach a measurement end Charlie, the first optical pulse and the second optical pulse are respectively reflected to a Q plate Q-plate2 and a Q plate Q-plate3 by a reflector Mirror1 and a Mirror3, demodulated by a Q plate Q-plate2 and a Q plate Q-plate4, respectively reflected to an optical fiber collimator Col3 and a Col4 by a transmitting Mirror Mirror2 and a Mirror4, and coupled into an optical fiber by an optical fiber collimator Col3 and Col4, and transmitted to a BSM measuring instrument for Bell state measurement.
2. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 1, wherein: the first transmitting end sagnac loop comprises a polarization beam splitter PBS1, a variable optical attenuator VOA1, a phase modulator PMA and an optical rotator 1; the polarization beam splitter PBS1, the variable optical attenuator VOA1, the phase modulator PMA and the optical rotator1 are connected in series by adopting polarization-maintaining optical fibers in sequence;
the polarizing beam splitter PBS1 is used for splitting 45-degree linearly polarized light into first horizontally polarized light and first vertically polarized light;
the phase modulator PMA is used for modulating the phase of polarized light in a clockwise or counterclockwise direction;
the light rotator1 is used for rotating the horizontal polarized light propagating clockwise by 90 ° to the vertical polarized light and rotating the vertical polarized light propagating counterclockwise by 90 ° to the horizontal polarized light;
the first horizontal polarized light and the first vertical polarized light are respectively transmitted in the polarization-maintaining optical fiber clockwise and anticlockwise; the first horizontally polarized light sequentially passes through the variable optical attenuator VOA1, the phase modulator PMA and the optical rotator1 to reach the polarization beam splitter PBS1, and the first vertically polarized light sequentially passes through the optical rotator1, the phase modulator PMA and the variable optical attenuator VOA1 to reach the polarization beam splitter PBS1 and is merged with the first horizontally polarized light reaching the polarization beam splitter PBS 1.
3. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 2, wherein: the phase modulator PMA is arranged at one end close to the vertical polarized light outlet of the polarization beam splitter PBS1, so that the first horizontal polarized light and the second vertical polarized light reach the phase modulator PMA with a time difference, and the time difference is used for modulating the phase of the required clockwise and anticlockwise transmitted polarized light only in the clockwise or anticlockwise direction; when the phase modulator PMA loads the first vertically polarized light with a phase of 0, then output from the polarizing beam splitter PBS1 is | + >, representing bit 1; when the phase modulator PMA loads the first vertically polarized light by pi/2, then output from the polarizing beam splitter PBS1 is, | - >, representing bit 0.
4. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 3, wherein: the second transmitting end sagnac loop comprises a polarization beam splitter PBS2, a variable optical attenuator VOA2, a phase modulator PMB and an optical rotator 2;
the polarization beam splitter PBS2, the variable optical attenuator VOA2, the phase modulator PMB and the optical rotator2 are connected in series by adopting polarization-maintaining optical fibers in sequence;
the polarization beam splitter PBS2 splits the 45-degree linearly polarized light into a second horizontally polarized light and a second vertically polarized light;
the phase modulator PMB is used for modulating the phase of polarized light in a clockwise direction or a counterclockwise direction;
the light rotator2 is used for rotating the horizontal polarized light propagating clockwise by 90 ° to the vertical polarized light and the vertical polarized light propagating counterclockwise by 90 ° to the horizontal polarized light;
the second horizontally polarized light and the second vertically polarized light are respectively transmitted in the polarization maintaining optical fiber clockwise and counterclockwise, the second horizontally polarized light sequentially passes through the variable optical attenuator VOA2, the phase modulator PMB and the optical rotator2 to reach the polarization beam splitter PBS2, and the second vertically polarized light sequentially passes through the optical rotator2, the phase modulator PMB and the variable optical attenuator VOA2 to reach the polarization beam splitter PBS 2.
5. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 4, wherein: the phase modulator PMB is placed at one end close to the vertical polarized light outlet of the polarization beam splitter PBS2, so that the second horizontal polarized light and the second vertical polarized light reach the phase modulator PMB with a time difference, and the time difference is that the clockwise and counterclockwise polarized light required for modulating the phase only modulates the phase in the clockwise or counterclockwise direction; when phase modulator PMB loads the vertically polarized light with a phase of 0, then output from polarizing beam splitter PBS2 is | + >, representing bit 1; when the phase modulator PMB loads the vertically polarized light by pi/2, then output from polarizing beamsplitter PBS2 is, | - >, representing bit 0.
6. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 5, wherein: the clockwise propagating optical pulses of the first and second horizontally polarized lightHas a polarization state of | H>By adjusting the phase modulator to
The polarization state of the light pulse of the first vertically polarized light and the second vertically polarized light propagating counterclockwise is | V>By adjusting the phase modulators PMA and PMB may be changed to
The quantum state of the light pulse when the vertically polarized light and the horizontally polarized light were combined at polarizing beam splitter PBS1 was
7. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 6, wherein: the Q-plate1 and Q-plate4 will polarize state | H>Into a quantum state
Will polarize the state | V>Into a quantum state
Will polarize the state | +>Conversion into quantum state
Polarization state | ->Conversion to a quantum state
Wherein R>Represents a right-handed circularly polarized state, | L>Represents a left-hand circular polarization state, | l ═ 1>Represents a state with an orbital angular momentum topological charge value of 1, | 1 ═ 1>Representing a state with an orbital angular momentum topological charge value of-1.
8. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 7, wherein: the Q plate Q-plate2 and the Q plate Q-plate3 convert quantum states
Is converted back to polarization state | H>Will be
Is converted back to the polarization state | V>Quantum state of the quantum
Is converted back to polarization state | +>Quantum state of the quantum
Polarization state of polarization | ->。
9. The sagnac-loop-based reference-system-independent measurement device-independent QKD system of claim 1, wherein: the BSM measuring instrument can only measure the polarization state | psi generated by the combination of two paths of signals through the beam splitter BS+>And | ψ->When the polarization state of the optical pulse is measured to be | ψ+>Time, single photon detector D1HAnd D1VOr D2HAnd D2VIn response, when the polarization state of the light pulse is measured as | ψ->Time, single photon detector D1HAnd D2VOr D2HAnd D1VAnd respond at the same time.
10. A sagnac loop-based reference system-independent measurement device-independent QKD method applied to a sagnac loop-based reference system-independent measurement device-independent QKD system according to any of claims 1-9, the method comprising the steps of:
s1, an emitting end Alice and an emitting end Bob serve as two communication parties to simultaneously send quantum signals, polarization information is loaded by loading phases through a sagnac loop, when a phase modulator does not modulate and a variable optical attenuator VOA blocks a counterclockwise pulse, a polarization state | H > is loaded, when the phase modulator does not modulate and the VOA blocks a clockwise pulse, a polarization state | V > is loaded, when the phase modulator modulates 0 degree of horizontal polarization light and the variable optical attenuator VOA does not modulate, a polarization state | plus > is loaded, when the phase modulator modulates pi of the horizontal polarization light, a polarization state | minus is loaded, and the signals are coupled through a Q board and then sent to a measuring end Charlie through a free space channel.
S2, enabling two paths of quantum signals to reach a measuring end Charlie, decoupling polarization and orbital angular momentum through two Q plates, and then entering a BSM measuring instrument for measurement, wherein when the polarization state of optical pulses is measured to be | psi+>Time, single photon detector D1HAnd D1VOr D2HAnd D2VIn response, when the polarization state of the light pulse is measured as | ψ->Time, single photon detector D1HAnd D2VOr D2HAnd D1VResponding at the same time;
s3, the measurement end Charlie publishes the measurement result of the BSM measuring instrument through a classical channel, and the two communication parties obtain the detection result from the measurement end Charlie;
s4, the transmitting end Alice publishes the base selection condition through a classical channel, and the transmitting end Bob omits a detection result different from the base selection condition of the transmitting end Alice to obtain an original secret key;
s5, the transmitting terminal Bob selects part of the keys to carry out error code detection; if the error rate exceeds the set threshold, the existence of an eavesdropper is proved, the result is discarded, and the process is restarted; if the error rate does not exceed the set threshold, continuing the next operation;
s6, post-processing the original key to obtain a usable security key.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101281339A (en) * | 2007-04-05 | 2008-10-08 | 电子科技大学 | Optical A/D converter of Sagnac structure |
| CN105897413A (en) * | 2016-05-26 | 2016-08-24 | 安徽问天量子科技股份有限公司 | Phase modulation polarization coded QKD system based on sagnac ring |
| CN111464302A (en) * | 2020-05-10 | 2020-07-28 | 神盾迅波(北京)量子科技发展有限公司 | Quantum key distribution system based on B92 protocol |
-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101281339A (en) * | 2007-04-05 | 2008-10-08 | 电子科技大学 | Optical A/D converter of Sagnac structure |
| CN105897413A (en) * | 2016-05-26 | 2016-08-24 | 安徽问天量子科技股份有限公司 | Phase modulation polarization coded QKD system based on sagnac ring |
| CN111464302A (en) * | 2020-05-10 | 2020-07-28 | 神盾迅波(北京)量子科技发展有限公司 | Quantum key distribution system based on B92 protocol |
Non-Patent Citations (1)
| Title |
|---|
| 孙佰利;何新龙;: "基于Sagnac环的环型量子密钥网络", 河北北方学院学报(自然科学版), no. 04 * |
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