Quantum secure direct communication(QSDC) is a communication method based on quantum mechanics and it is used to transmit secret messages. Unlike quantum key distribution, secret messages can be transmitted directly o...Quantum secure direct communication(QSDC) is a communication method based on quantum mechanics and it is used to transmit secret messages. Unlike quantum key distribution, secret messages can be transmitted directly on a quantum channel with QSDC. Higher channel capacity and noise suppression capabilities are key to achieving longdistance quantum communication. Here, we report a continuous-variable QSDC scheme based on mask-coding and orbital angular momentum, in which the mask-coding is employed to protect the security of the transmitting messages and to suppress the influence of excess noise. The combination of orbital angular momentum and information block transmission effectively improves the secrecy capacity. In the 800 information blocks ×1310 bits length 10-km experiment, the results show a statistical average bit error rate of 0.38%, a system excess noise value of 0.0184 SNU, and a final secrecy capacity of 6.319×10~6 bps. Therefore, this scheme reduces error bits while increasing secrecy capacity, providing a solution for long-distance large-scale quantum communication, which is capable of transmitting text, images and other information of reasonable size.展开更多
As the cornerstone of future information security,quantum key distribution(QKD)is evolving towards large-scale hybrid discrete-variable/continuous-variable(DV/CV)multi-domain quantum networks.Meanwhile,multicast-orien...As the cornerstone of future information security,quantum key distribution(QKD)is evolving towards large-scale hybrid discrete-variable/continuous-variable(DV/CV)multi-domain quantum networks.Meanwhile,multicast-oriented multi-party key negotiation is attracting increasing attention in quantum networks.However,the efficient key provision for multicast services over hybrid DV/CV multi-domain quantum networks remains challenging,due to the limited probability of service success and the inefficient utilization of key resources.Targeting these challenges,this study proposes two key-resource-aware multicast-oriented key provision strategies,namely the link distance-resource balanced key provision strategy and the maximum shared link key provision strategy.The proposed strategies are applicable to hybrid DV/CV multi-domain quantum networks,which are typically implemented by GG02-based intra-domain connections and BB84-based inter-domain connections.Furthermore,the multicast-oriented key provision model is formulated,based on which two heuristic algorithms are designed,i.e.,the shared link distance-resource(SLDR)dependent and the maximum shared link distance-resource(MSLDR)dependent multicast-oriented key provision algorithms.Simulation results verify the applicability of the designed algorithms across different multi-domain quantum networks,and demonstrate their superiority over the benchmark algorithms in terms of the success probability of multicast service requests,the number of shared links,and the key resource utilization.展开更多
NWA 16080 is a representative reduced CV carbonaceous chondrite(CV_(red)),consisting mainly of chon-drules(47 vol%)and matrix(42 vol%),along with minor quantities of calcium-and aluminum-rich inclusions(CAI)and amoebo...NWA 16080 is a representative reduced CV carbonaceous chondrite(CV_(red)),consisting mainly of chon-drules(47 vol%)and matrix(42 vol%),along with minor quantities of calcium-and aluminum-rich inclusions(CAI)and amoeboid olivine aggregates(AOA)(CAI+AOA,6 vol%)and opaque minerals(5 vol%).The chondrules exhibit well-preserved outlines and can be categorized into Type Ⅰ(Fa<10)and Type Ⅱ(Fa>10).They primarily consist of magnesium-rich olivine,along with both low-Ca and high-Ca pyroxenes,and contain minor amounts of secondary plagioclase.Olivines present in chondrules display compositional zoning characterized whereas the matrix is composed of fine-grained olivine.Nickel-rich metal and nickel-poor sulfides are also present,along with trace amounts of magnetite.In contrast to standard oxidized CV chondrites(CV_(ox)),the presence of high metal,Ni-poor sulfides,and reduced magnetite in NWA 16080 indicates a more reduced parent-body environment.Shock metamorphism is classified as mild(S1),while terrestrial weathering is characterized as low(W2).Raman spectroscopy indicates a diverse spectrum of organic matter(OM)maturity:certain areas exhibit characteristics akin to other CV_(red) chondrites,whereas others reach maturity levels comparable to those observed in CV_(ox) chondrites.The Raman parameters indicate that this meteorite is classified as approximately type 3.4 to 3.5.The overlapping OM maturity with certain CV_(ox) chondrites provides a contradiction to the anticipated depth-thermal layering outlined in the onion-shell model.This suggests that the CV parent body probably experienced more intricate processes,including impacts and fluid-rock interactions,rather than merely depth-dependent heating.展开更多
为了解引起2017年10月甘肃省兰州市一起疱疹性咽峡炎(Herpangina,HA)暴发疫情的致病病原体及其病原学特征,对采集的患儿的37份咽拭子样本开展病毒分离培养,然后对分离到的毒株采取一代测序获取VP1区全长核苷酸序列,根据分子定型的方法...为了解引起2017年10月甘肃省兰州市一起疱疹性咽峡炎(Herpangina,HA)暴发疫情的致病病原体及其病原学特征,对采集的患儿的37份咽拭子样本开展病毒分离培养,然后对分离到的毒株采取一代测序获取VP1区全长核苷酸序列,根据分子定型的方法进行肠道病毒型别鉴定。根据VP1区核苷酸差异选择3个毒株进行二代测序,获取全基因组序列。使用MEGA软件(版本号11.0)进行病毒的核苷酸,氨基酸相似性分析,VP1区的氨基酸突变位点分析,并构建系统发育树,使用Simplot(版本号3.5.1)软件进行病毒重组分析。本次疫情中分离到的毒株鉴定为柯萨奇病毒A2型(Coxsackievirus A 2, CV-A2),分子分型显示属于D基因型,且VP1区第102位氨基酸发生了丙氨酸到甘氨酸(A102G)的突变,与省内2014-2015年分离到的两株CV-A2毒株在该位置的突变不同。重组分析发现,病毒在P2区和P3区发生了以CV-A4为主的重组事件。本次疫情的致病病原体CV-A2存在着VP1区氨基酸A102G的特征性变异及P2区和P3区的重组,需要加强对肠道病毒的变异和重组的监测和研究,以提升预警能力。展开更多
The well-known multi-dimensional reconciliation is an effective method used in the continuous-variable quantum key distribution in the long-distance and the low signal-to-noise-ratio scenarios.The virtual channel empl...The well-known multi-dimensional reconciliation is an effective method used in the continuous-variable quantum key distribution in the long-distance and the low signal-to-noise-ratio scenarios.The virtual channel employed to exchange data is generally established by using a finite-dimensional rotation in the reconciliation procedure.In this paper,we found that the finite dimension of the multi-dimensional reconciliation inevitably leads to the mismatch of the signal-to-noise-ratio between the quantum channel and the virtual channel,which may be called the finite-dimension effect.Such an effect results in an overestimation on the secret key rate,and subsequently induces vital practical security loopholes.展开更多
Considering the ocean water＇s optical attenuation and the roughness of the sea surface, we analyze the security of continuous-variable （CV） quantum key distribution （QKD） based Mr-to-water channel. The effects of...Considering the ocean water＇s optical attenuation and the roughness of the sea surface, we analyze the security of continuous-variable （CV） quantum key distribution （QKD） based Mr-to-water channel. The effects of the absorp- tion and scattering on the transmittance of underwater quantum channel and the maximum secure transmission distance are studied. Considering the roughness of the sea surface, we simulate the performance bounds of CV QKD with different wind speeds using the Monte Carlo method. The results show that even if the secret key rate gradually reduces as the wind speed increases, the maximum transmission distance will not be affected obviously. Compared to the works regarding short-distance underwater optical communication, our research represents a significant step towards establishing secure communication between air platform and submarine vehicle.展开更多
Continuous-variable quantum key distribution(CVQKD) protocols with entanglement in the middle(EM) enable long maximal transmission distances for quantum communications. For the security analysis of the protocols, it i...Continuous-variable quantum key distribution(CVQKD) protocols with entanglement in the middle(EM) enable long maximal transmission distances for quantum communications. For the security analysis of the protocols, it is usually assumed that Eve performs collective Gaussian attacks and there is a lack of finite-size analysis of the protocols. However,in this paper we consider the finite-size regime of the EM-based CVQKD protocols by exposing the protocol to collective attacks and coherent attacks. We differentiate between the collective attacks and the coherent attacks while comparing asymptotic key rate and the key rate in the finite-size scenarios. Moreover, both symmetric and asymmetric configurations are collated in a contrastive analysis. As expected, the derived results in the finite-size scenarios are less useful than those acquired in the asymptotic regime. Nevertheless, we find that CVQKD with entanglement in the middle is capable of providing fully secure secret keys taking the finite-size effects into account with transmission distances of more than 30 km.展开更多
The developing tendency of continuous-variable （CV） measurement-device-independent （MDI） quantum cryptography is to cope with the practical issue of implementing sealable quantum networks. Up to now, most theoreti...The developing tendency of continuous-variable （CV） measurement-device-independent （MDI） quantum cryptography is to cope with the practical issue of implementing sealable quantum networks. Up to now, most theoretical and experimental researches on CV-MDI QKD are focused on two-party protocols. However, we suggest a CV-MDI multipartite quantum secret sharing （QSS） protocol use the EPR states coupled with optical amplifiers. More remarkable, QSS is the real application in multipartite CV-MDI QKD, in other words, is the concrete implementation method of multipartite CV-MDI QKD. It can implement a practical quantum network scheme, under which the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger （GHZ） state analysis at relay station. Even if there is a possibility that the relay may be completely tampered, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Additionally, we illustrate that the use of optical amplifiers can compensate the partial inherent imperfections of detectors and increase the transmission distance of the CV-MDI quantum system.展开更多
We investigate the time evolution of quantum correlations, which are measured by Gaussian quantum discord in a continuous-variable bipartite system subject to common and independent non-Markovian environments. Conside...We investigate the time evolution of quantum correlations, which are measured by Gaussian quantum discord in a continuous-variable bipartite system subject to common and independent non-Markovian environments. Considering an initial two-mode Gaussian symmetric squeezed thermal state, we show that quantum correlations can be created during the non-Markovian evolution, which is different from the Markovian process. Furthermore, we find that the temperature is a key factor during the evolution in non-Markovian environments. For common reservoirs, a maximum creation of quantum correlations may occur under an appropriate temperature. For independent reservoirs, the non-Markovianity of the total system corresponds to the subsystem whose temperature is higher. In both common and independent environments, the Gaussian quantum discord is influenced by the temperature and the photon number of each mode.展开更多
Information reconciliation is a significant step for a continuous-variable quantum key distribution（CV-QKD） system.We propose a reconciliation method that allows two authorized parties to extract a consistent and se...Information reconciliation is a significant step for a continuous-variable quantum key distribution（CV-QKD） system.We propose a reconciliation method that allows two authorized parties to extract a consistent and secure binary key in a CV-QKD protocol,which is based on Gaussian-modulated coherent states and homodyne detection.This method named spherical reconciliation is based on spherical quantization and non-binary low-density parity-check（LDPC） codes.With the suitable signal-to-noise ratio（SNR） and code rate of non-binary LDPC codes,spherical reconciliation algorithm has a high efficiency and can extend the transmission distance of CV-QKD.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62071381 and 62301430)Shaanxi Fundamental Science Research Project for Mathematics and Physics (Grant No. 23JSY014)+1 种基金Scientific Research Plan Project of Shaanxi Education Department (Natural Science Special Project (Grant No. 23JK0680)Young Talent Fund of Xi’an Association for Science and Technology (Grant No. 959202313011)。
文摘Quantum secure direct communication(QSDC) is a communication method based on quantum mechanics and it is used to transmit secret messages. Unlike quantum key distribution, secret messages can be transmitted directly on a quantum channel with QSDC. Higher channel capacity and noise suppression capabilities are key to achieving longdistance quantum communication. Here, we report a continuous-variable QSDC scheme based on mask-coding and orbital angular momentum, in which the mask-coding is employed to protect the security of the transmitting messages and to suppress the influence of excess noise. The combination of orbital angular momentum and information block transmission effectively improves the secrecy capacity. In the 800 information blocks ×1310 bits length 10-km experiment, the results show a statistical average bit error rate of 0.38%, a system excess noise value of 0.0184 SNU, and a final secrecy capacity of 6.319×10~6 bps. Therefore, this scheme reduces error bits while increasing secrecy capacity, providing a solution for long-distance large-scale quantum communication, which is capable of transmitting text, images and other information of reasonable size.
基金supported by the National Natural Science Foundation of China(Grant Nos.62201276,62350001,U22B2026,and 62425105)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300701)the Key R&D Program(Industry Foresight and Key Core Technologies)of Jiangsu Province(Grant No.BE2022071)。
文摘As the cornerstone of future information security,quantum key distribution(QKD)is evolving towards large-scale hybrid discrete-variable/continuous-variable(DV/CV)multi-domain quantum networks.Meanwhile,multicast-oriented multi-party key negotiation is attracting increasing attention in quantum networks.However,the efficient key provision for multicast services over hybrid DV/CV multi-domain quantum networks remains challenging,due to the limited probability of service success and the inefficient utilization of key resources.Targeting these challenges,this study proposes two key-resource-aware multicast-oriented key provision strategies,namely the link distance-resource balanced key provision strategy and the maximum shared link key provision strategy.The proposed strategies are applicable to hybrid DV/CV multi-domain quantum networks,which are typically implemented by GG02-based intra-domain connections and BB84-based inter-domain connections.Furthermore,the multicast-oriented key provision model is formulated,based on which two heuristic algorithms are designed,i.e.,the shared link distance-resource(SLDR)dependent and the maximum shared link distance-resource(MSLDR)dependent multicast-oriented key provision algorithms.Simulation results verify the applicability of the designed algorithms across different multi-domain quantum networks,and demonstrate their superiority over the benchmark algorithms in terms of the success probability of multicast service requests,the number of shared links,and the key resource utilization.
基金supported by National Natural Science Foundation of China(grant no.42403041)Scientific Base and Talent Special Projects of Guangxi(grant no.AD23026084)Scientific Research Foundation of Guilin University of Technology(GUTQDJJ6614023).
文摘NWA 16080 is a representative reduced CV carbonaceous chondrite(CV_(red)),consisting mainly of chon-drules(47 vol%)and matrix(42 vol%),along with minor quantities of calcium-and aluminum-rich inclusions(CAI)and amoeboid olivine aggregates(AOA)(CAI+AOA,6 vol%)and opaque minerals(5 vol%).The chondrules exhibit well-preserved outlines and can be categorized into Type Ⅰ(Fa<10)and Type Ⅱ(Fa>10).They primarily consist of magnesium-rich olivine,along with both low-Ca and high-Ca pyroxenes,and contain minor amounts of secondary plagioclase.Olivines present in chondrules display compositional zoning characterized whereas the matrix is composed of fine-grained olivine.Nickel-rich metal and nickel-poor sulfides are also present,along with trace amounts of magnetite.In contrast to standard oxidized CV chondrites(CV_(ox)),the presence of high metal,Ni-poor sulfides,and reduced magnetite in NWA 16080 indicates a more reduced parent-body environment.Shock metamorphism is classified as mild(S1),while terrestrial weathering is characterized as low(W2).Raman spectroscopy indicates a diverse spectrum of organic matter(OM)maturity:certain areas exhibit characteristics akin to other CV_(red) chondrites,whereas others reach maturity levels comparable to those observed in CV_(ox) chondrites.The Raman parameters indicate that this meteorite is classified as approximately type 3.4 to 3.5.The overlapping OM maturity with certain CV_(ox) chondrites provides a contradiction to the anticipated depth-thermal layering outlined in the onion-shell model.This suggests that the CV parent body probably experienced more intricate processes,including impacts and fluid-rock interactions,rather than merely depth-dependent heating.
文摘为了解引起2017年10月甘肃省兰州市一起疱疹性咽峡炎(Herpangina,HA)暴发疫情的致病病原体及其病原学特征,对采集的患儿的37份咽拭子样本开展病毒分离培养,然后对分离到的毒株采取一代测序获取VP1区全长核苷酸序列,根据分子定型的方法进行肠道病毒型别鉴定。根据VP1区核苷酸差异选择3个毒株进行二代测序,获取全基因组序列。使用MEGA软件(版本号11.0)进行病毒的核苷酸,氨基酸相似性分析,VP1区的氨基酸突变位点分析,并构建系统发育树,使用Simplot(版本号3.5.1)软件进行病毒重组分析。本次疫情中分离到的毒株鉴定为柯萨奇病毒A2型(Coxsackievirus A 2, CV-A2),分子分型显示属于D基因型,且VP1区第102位氨基酸发生了丙氨酸到甘氨酸(A102G)的突变,与省内2014-2015年分离到的两株CV-A2毒株在该位置的突变不同。重组分析发现,病毒在P2区和P3区发生了以CV-A4为主的重组事件。本次疫情的致病病原体CV-A2存在着VP1区氨基酸A102G的特征性变异及P2区和P3区的重组,需要加强对肠道病毒的变异和重组的监测和研究,以提升预警能力。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61332019,61671287,and 61631014)the National Key Research and Development Program of China(Grant No.2016YFA0302600)
文摘The well-known multi-dimensional reconciliation is an effective method used in the continuous-variable quantum key distribution in the long-distance and the low signal-to-noise-ratio scenarios.The virtual channel employed to exchange data is generally established by using a finite-dimensional rotation in the reconciliation procedure.In this paper,we found that the finite dimension of the multi-dimensional reconciliation inevitably leads to the mismatch of the signal-to-noise-ratio between the quantum channel and the virtual channel,which may be called the finite-dimension effect.Such an effect results in an overestimation on the secret key rate,and subsequently induces vital practical security loopholes.
基金Supported by the National Natural Science Foundation of China under Grant No 61572529
文摘Considering the ocean water＇s optical attenuation and the roughness of the sea surface, we analyze the security of continuous-variable （CV） quantum key distribution （QKD） based Mr-to-water channel. The effects of the absorp- tion and scattering on the transmittance of underwater quantum channel and the maximum secure transmission distance are studied. Considering the roughness of the sea surface, we simulate the performance bounds of CV QKD with different wind speeds using the Monte Carlo method. The results show that even if the secret key rate gradually reduces as the wind speed increases, the maximum transmission distance will not be affected obviously. Compared to the works regarding short-distance underwater optical communication, our research represents a significant step towards establishing secure communication between air platform and submarine vehicle.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61572529,61871407,and 61801522)the China Postdoctoral Science Foundation(Grant Nos.2013M542119 and 2014T70772)
文摘Continuous-variable quantum key distribution(CVQKD) protocols with entanglement in the middle(EM) enable long maximal transmission distances for quantum communications. For the security analysis of the protocols, it is usually assumed that Eve performs collective Gaussian attacks and there is a lack of finite-size analysis of the protocols. However,in this paper we consider the finite-size regime of the EM-based CVQKD protocols by exposing the protocol to collective attacks and coherent attacks. We differentiate between the collective attacks and the coherent attacks while comparing asymptotic key rate and the key rate in the finite-size scenarios. Moreover, both symmetric and asymmetric configurations are collated in a contrastive analysis. As expected, the derived results in the finite-size scenarios are less useful than those acquired in the asymptotic regime. Nevertheless, we find that CVQKD with entanglement in the middle is capable of providing fully secure secret keys taking the finite-size effects into account with transmission distances of more than 30 km.
基金Supported by National Natural Science Foundation of China under Grant Nos.61379153,61579725
文摘The developing tendency of continuous-variable （CV） measurement-device-independent （MDI） quantum cryptography is to cope with the practical issue of implementing sealable quantum networks. Up to now, most theoretical and experimental researches on CV-MDI QKD are focused on two-party protocols. However, we suggest a CV-MDI multipartite quantum secret sharing （QSS） protocol use the EPR states coupled with optical amplifiers. More remarkable, QSS is the real application in multipartite CV-MDI QKD, in other words, is the concrete implementation method of multipartite CV-MDI QKD. It can implement a practical quantum network scheme, under which the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger （GHZ） state analysis at relay station. Even if there is a possibility that the relay may be completely tampered, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Additionally, we illustrate that the use of optical amplifiers can compensate the partial inherent imperfections of detectors and increase the transmission distance of the CV-MDI quantum system.
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant Nos.2013-Ia-032 and WUT:2014-Ia-026)
文摘We investigate the time evolution of quantum correlations, which are measured by Gaussian quantum discord in a continuous-variable bipartite system subject to common and independent non-Markovian environments. Considering an initial two-mode Gaussian symmetric squeezed thermal state, we show that quantum correlations can be created during the non-Markovian evolution, which is different from the Markovian process. Furthermore, we find that the temperature is a key factor during the evolution in non-Markovian environments. For common reservoirs, a maximum creation of quantum correlations may occur under an appropriate temperature. For independent reservoirs, the non-Markovianity of the total system corresponds to the subsystem whose temperature is higher. In both common and independent environments, the Gaussian quantum discord is influenced by the temperature and the photon number of each mode.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1304613 and 11204379)
文摘Information reconciliation is a significant step for a continuous-variable quantum key distribution（CV-QKD） system.We propose a reconciliation method that allows two authorized parties to extract a consistent and secure binary key in a CV-QKD protocol,which is based on Gaussian-modulated coherent states and homodyne detection.This method named spherical reconciliation is based on spherical quantization and non-binary low-density parity-check（LDPC） codes.With the suitable signal-to-noise ratio（SNR） and code rate of non-binary LDPC codes,spherical reconciliation algorithm has a high efficiency and can extend the transmission distance of CV-QKD.
