In this paper, we propose a measurement-device-independent quantum-key-distribution（MDI-QKD） protocol using orbital angular momentum（OAM） in free space links, named the OAM-MDI-QKD protocol. In the proposed protoc...In this paper, we propose a measurement-device-independent quantum-key-distribution（MDI-QKD） protocol using orbital angular momentum（OAM） in free space links, named the OAM-MDI-QKD protocol. In the proposed protocol,the OAM states of photons, instead of polarization states, are used as the information carriers to avoid the reference frame alignment, the decoy-state is adopted to overcome the security loophole caused by the weak coherent pulse source, and the high efficient OAM-sorter is adopted as the measurement tool for Charlie to obtain the output OAM state. Here, Charlie may be an untrusted third party. The results show that the authorized users, Alice and Bob, could distill a secret key with Charlie＇s successful measurements, and the key generation performance is slightly better than that of the polarization-based MDI-QKD protocol in the two-dimensional OAM cases. Simultaneously, Alice and Bob can reduce the number of flipping the bits in the secure key distillation. It is indicated that a higher key generation rate performance could be obtained by a high dimensional OAM-MDI-QKD protocol because of the unlimited degree of freedom on OAM states. Moreover,the results show that the key generation rate and the transmission distance will decrease as the growth of the strength of atmospheric turbulence（AT） and the link attenuation. In addition, the decoy states used in the proposed protocol can get a considerable good performance without the need for an ideal source.展开更多
The effects of weather conditions are ubiquitous in practical wireless quantum communication links.Here in this work,the performances of atmospheric continuous-variable measurement-device-independent quantum key distr...The effects of weather conditions are ubiquitous in practical wireless quantum communication links.Here in this work,the performances of atmospheric continuous-variable measurement-device-independent quantum key distribution(CV-MDI-QKD)under diverse weather conditions are analyzed quantitatively.According to the Mie scattering theory and atmospheric CV-MDI-QKD model,we numerically simulate the relationship between performance of CV-MDI-QKD and the rainy and foggy conditions,aiming to get close to the actual combat environment in the future.The results show that both rain and fog will degrade the performance of the CV-MDI-QKD protocol.Under the rainy condition,the larger the raindrop diameter,the more obvious the extinction effect is and the lower the secret key rate accordingly.In addition,we find that the secret key rate decreases with the increase of spot deflection distance and the fluctuation of deflection.Under the foggy condition,the results illustrate that the transmittance decreases with the increase of droplet radius or deflection distance,which eventually yields the decrease in the secret key rate.Besides,in both weather conditions,the increase of transmission distance also leads the secret key rate to deteriorate.Our work can provide a foundation for evaluating the performance evaluation and successfully implementing the atmospheric CV-MDI-QKD in the future field operation environment under different weather conditions.展开更多
A measurement-device-independent quantum key distribution(MDI-QKD) method with an air-water channel is researched. In this method, the underwater vehicle and satellite are the legitimate parties, and the third party i...A measurement-device-independent quantum key distribution(MDI-QKD) method with an air-water channel is researched. In this method, the underwater vehicle and satellite are the legitimate parties, and the third party is at the airwater interface in order to simplify the unilateral quantum channel to water or air. Considering the condition that both unilateral transmission distance and transmission loss coefficient are unequal, a perfect model of the asymmetric channel is built. The influence of asymmetric channel on system loss tolerance and secure transmission distance is analyzed. The simulation results show that with the increase of the channel's asymmetric degree, the system loss tolerance will descend, one transmission distance will be reduced while the other will be increased. When the asymmetric coefficient of channel is between 0.068 and 0.171, MDI-QKD can satisfy the demand of QKD with an air-water channel, namely the underwater transmission distance and atmospheric transmission distance are not less than 60 m and 12 km, respectively.展开更多
Measurement device-independent quantum key distribution(MDI-QKD) protocols are immune to all possible attacks on the photon detectors during quantum communication, but their key generation rates are low compared with ...Measurement device-independent quantum key distribution(MDI-QKD) protocols are immune to all possible attacks on the photon detectors during quantum communication, but their key generation rates are low compared with those of other QKD schemes.Increasing each individual photon’s channel capacity is an efficient way to increase the key generation rate, and high-dimensional(HD) encoding is a powerful tool for increasing the channel capacity of photons. In this paper, we propose an HD MDI-QKD protocol with qudits hyper-encoded in spatial mode and polarization degrees of freedom(DOFs). In the proposed protocol, keys can be generated using the spatial mode and polarization DOFs simultaneously. The proposed protocol is unconditionally secure,even for weak coherent pulses with decoy states. The proposed MDI-QKD protocol may be useful for future quantum secure communication applications.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61271238 and 61475075)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20123223110003)+7 种基金the Natural Science Research Foundation for Universities of Jiangsu Province of China(Grant No.11KJA510002)the Open Research Fund of Key Laboratory of Broadband Wireless Communication and Sensor Network TechnologyMinistry of EducationChina(Grant No.NYKL2015011)the Innovation Program of Graduate Education of Jiangsu ProvinceChina(Grant No.KYLX0810)partially supported by Qinglan Project of Jiangsu ProvinceChina
文摘In this paper, we propose a measurement-device-independent quantum-key-distribution（MDI-QKD） protocol using orbital angular momentum（OAM） in free space links, named the OAM-MDI-QKD protocol. In the proposed protocol,the OAM states of photons, instead of polarization states, are used as the information carriers to avoid the reference frame alignment, the decoy-state is adopted to overcome the security loophole caused by the weak coherent pulse source, and the high efficient OAM-sorter is adopted as the measurement tool for Charlie to obtain the output OAM state. Here, Charlie may be an untrusted third party. The results show that the authorized users, Alice and Bob, could distill a secret key with Charlie＇s successful measurements, and the key generation performance is slightly better than that of the polarization-based MDI-QKD protocol in the two-dimensional OAM cases. Simultaneously, Alice and Bob can reduce the number of flipping the bits in the secure key distillation. It is indicated that a higher key generation rate performance could be obtained by a high dimensional OAM-MDI-QKD protocol because of the unlimited degree of freedom on OAM states. Moreover,the results show that the key generation rate and the transmission distance will decrease as the growth of the strength of atmospheric turbulence（AT） and the link attenuation. In addition, the decoy states used in the proposed protocol can get a considerable good performance without the need for an ideal source.
基金Project supported by the National Natural Science Foundation of China(Grant No.61505261).
文摘The effects of weather conditions are ubiquitous in practical wireless quantum communication links.Here in this work,the performances of atmospheric continuous-variable measurement-device-independent quantum key distribution(CV-MDI-QKD)under diverse weather conditions are analyzed quantitatively.According to the Mie scattering theory and atmospheric CV-MDI-QKD model,we numerically simulate the relationship between performance of CV-MDI-QKD and the rainy and foggy conditions,aiming to get close to the actual combat environment in the future.The results show that both rain and fog will degrade the performance of the CV-MDI-QKD protocol.Under the rainy condition,the larger the raindrop diameter,the more obvious the extinction effect is and the lower the secret key rate accordingly.In addition,we find that the secret key rate decreases with the increase of spot deflection distance and the fluctuation of deflection.Under the foggy condition,the results illustrate that the transmittance decreases with the increase of droplet radius or deflection distance,which eventually yields the decrease in the secret key rate.Besides,in both weather conditions,the increase of transmission distance also leads the secret key rate to deteriorate.Our work can provide a foundation for evaluating the performance evaluation and successfully implementing the atmospheric CV-MDI-QKD in the future field operation environment under different weather conditions.
基金supported by the National Natural Science Foundation of China(No.61302099)
文摘A measurement-device-independent quantum key distribution(MDI-QKD) method with an air-water channel is researched. In this method, the underwater vehicle and satellite are the legitimate parties, and the third party is at the airwater interface in order to simplify the unilateral quantum channel to water or air. Considering the condition that both unilateral transmission distance and transmission loss coefficient are unequal, a perfect model of the asymmetric channel is built. The influence of asymmetric channel on system loss tolerance and secure transmission distance is analyzed. The simulation results show that with the increase of the channel's asymmetric degree, the system loss tolerance will descend, one transmission distance will be reduced while the other will be increased. When the asymmetric coefficient of channel is between 0.068 and 0.171, MDI-QKD can satisfy the demand of QKD with an air-water channel, namely the underwater transmission distance and atmospheric transmission distance are not less than 60 m and 12 km, respectively.
基金supported by the National Natural Science Foundation of China(Grant No.11974189)the China Postdoctoral Science Foundation(Grant No.2018M642293)+1 种基金the open research fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology,Nanjing University of Posts and Telecommunications,Ministry of Education(Grant No.JZNY201908)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Measurement device-independent quantum key distribution(MDI-QKD) protocols are immune to all possible attacks on the photon detectors during quantum communication, but their key generation rates are low compared with those of other QKD schemes.Increasing each individual photon’s channel capacity is an efficient way to increase the key generation rate, and high-dimensional(HD) encoding is a powerful tool for increasing the channel capacity of photons. In this paper, we propose an HD MDI-QKD protocol with qudits hyper-encoded in spatial mode and polarization degrees of freedom(DOFs). In the proposed protocol, keys can be generated using the spatial mode and polarization DOFs simultaneously. The proposed protocol is unconditionally secure,even for weak coherent pulses with decoy states. The proposed MDI-QKD protocol may be useful for future quantum secure communication applications.
