Fast and accurate transient stability analysis is crucial to power system operation.With high penetration level of wind power resources,practical dynamic security region(PDSR)with hyper plane expression has outstandin...Fast and accurate transient stability analysis is crucial to power system operation.With high penetration level of wind power resources,practical dynamic security region(PDSR)with hyper plane expression has outstanding advantages in situational awareness and series of optimization problems.The precondition of obtaining accurate PDSR boundary is to locate sufficient points around the boundary(critical points).Therefore,this paper proposes a space division and Wasserstein generative adversarial network with gra-dient penalty(WGAN-GP)based fast generation method of PDSR boundary.First,the typical differential topological characterizations of dynamic security region(DSR)provide strong theoretical foundation that the interior of DSR is hole-free and the boundaries of DSR are tight and knot-free.Then,the space division method is proposed to calculate critical operation area where the PDSR boundary is located,tremen-dously compressing the search space to locate critical points and improving the confidence level of boundary fitting result.Furthermore,the WGAN-GP model is utilized to fast obtain large number of criti-cal points based on learning the data distribution of the small training set aforementioned.Finally,the PDSR boundary with hyperplanes is fitted by the least square method.The case study is tested on the Institute of Electrical and Electronics Engineers(IEEE)39-bus system and the results verify the accuracy and efficiency of the proposed method.展开更多
Recently,Long et al.[1]at the Beijing Academy of Quantum Information Sciences,in collaboration with the partners,proposed the theory of oneway quantum secure direct communication(QSDC)and successfully developed a prac...Recently,Long et al.[1]at the Beijing Academy of Quantum Information Sciences,in collaboration with the partners,proposed the theory of oneway quantum secure direct communication(QSDC)and successfully developed a practical system.This achievement set a world record for long-distance stable transmission,demonstrating a rate of 2.38 kbps at a distance of 104.8 km over 168 hours.展开更多
In practical quantum key distribution(QKD)systems,a single photon-detector(SPD)is one of the most vulnerable components.Faint after-gate attack is a universal attack against the detector.However,the original faint aft...In practical quantum key distribution(QKD)systems,a single photon-detector(SPD)is one of the most vulnerable components.Faint after-gate attack is a universal attack against the detector.However,the original faint after-gate attack can be discovered by monitoring the photocurrent.This paper presents a probabilistic generalization of the attack,which we refer to as probabilistic faint after-gate attack,by introducing probability control modules.Previous countermeasures for photocurrent monitoring may fail in detecting the eavesdropper under some specific probabilities.To mitigate this threat,we provide a method to determine the detectable boundary in the limitation of precision of photocurrent monitoring,and investigate the security of QKD systems under such boundaries using the weak randomness model.展开更多
Quantum secure direct communication provides a direct means of conveying secret information via quantum states among legitimate users.The past two decades have witnessed its great strides both theoretically and experi...Quantum secure direct communication provides a direct means of conveying secret information via quantum states among legitimate users.The past two decades have witnessed its great strides both theoretically and experimentally.However,the security analysis of it still stays in its infant.Some practical problems in this field to be solved urgently,such as detector efficiency mismatch,side-channel effect and source imperfection,are propelling the birth of a more impeccable solution.In this paper,we establish a new framework of the security analysis driven by numerics where all the practical problems may be taken into account naturally.We apply this framework to several variations of the DL04 protocol considering real-world experimental conditions.Also,we propose two optimizing methods to process the numerical part of the framework so as to meet different requirements in practice.With these properties considered,we predict the robust framework would open up a broad avenue of the development in the field.展开更多
Quantum key distribution(QKD)guarantees informationtheoretic security through the fundamental principles of quantum mechanics.As its matures,QKD networks have achieved long-distance deployment,showing significant adva...Quantum key distribution(QKD)guarantees informationtheoretic security through the fundamental principles of quantum mechanics.As its matures,QKD networks have achieved long-distance deployment,showing significant advancements in practical quantum-security communication infrastructure[1].When transitioning to large scale quantum communication networks with complicated topologies,conventional paradigms,which are based on point-to-point QKD links connected by trusted nodes,face technical challenges on achieving scalability and optimizing resource allocation.Quantum entanglements are important resources for quantum networks.展开更多
The security of quantum key distribution(QKD)is severely threatened by discrepancies between realistic devices and theoretical assumptions.Recently,a significant framework called the reference technique was proposed t...The security of quantum key distribution(QKD)is severely threatened by discrepancies between realistic devices and theoretical assumptions.Recently,a significant framework called the reference technique was proposed to provide security against arbitrary source flaws under current technology such as state preparation flaws,side channels caused by mode dependencies,the Trojan horse attacks and pulse correlations.Here,we adopt the reference technique to prove security of an efficient four-phase measurement-device-independent QKD using laser pulses against potential source imperfections.We present a characterization of source flaws and connect them to experiments,together with a finite-key analysis against coherent attacks.In addition,we demonstrate the feasibility of our protocol through a proof-of-principle experimental implementation and achieve a secure key rate of 253 bps with a 20 d B channel loss.Compared with previous QKD protocols with imperfect devices,our study considerably improves both the secure key rate and the transmission distance,and shows application potential in the practical deployment of secure QKD with device imperfections.展开更多
基金funded in part by the National Key Research and Development Program of China(2020YFB0905900)in part by Science and Technology Project of State Grid Corporation of China(SGCC)The Key Technologies for Electric Internet of Things(SGTJDK00DWJS2100223).
文摘Fast and accurate transient stability analysis is crucial to power system operation.With high penetration level of wind power resources,practical dynamic security region(PDSR)with hyper plane expression has outstanding advantages in situational awareness and series of optimization problems.The precondition of obtaining accurate PDSR boundary is to locate sufficient points around the boundary(critical points).Therefore,this paper proposes a space division and Wasserstein generative adversarial network with gra-dient penalty(WGAN-GP)based fast generation method of PDSR boundary.First,the typical differential topological characterizations of dynamic security region(DSR)provide strong theoretical foundation that the interior of DSR is hole-free and the boundaries of DSR are tight and knot-free.Then,the space division method is proposed to calculate critical operation area where the PDSR boundary is located,tremen-dously compressing the search space to locate critical points and improving the confidence level of boundary fitting result.Furthermore,the WGAN-GP model is utilized to fast obtain large number of criti-cal points based on learning the data distribution of the small training set aforementioned.Finally,the PDSR boundary with hyperplanes is fitted by the least square method.The case study is tested on the Institute of Electrical and Electronics Engineers(IEEE)39-bus system and the results verify the accuracy and efficiency of the proposed method.
文摘Recently,Long et al.[1]at the Beijing Academy of Quantum Information Sciences,in collaboration with the partners,proposed the theory of oneway quantum secure direct communication(QSDC)and successfully developed a practical system.This achievement set a world record for long-distance stable transmission,demonstrating a rate of 2.38 kbps at a distance of 104.8 km over 168 hours.
文摘In practical quantum key distribution(QKD)systems,a single photon-detector(SPD)is one of the most vulnerable components.Faint after-gate attack is a universal attack against the detector.However,the original faint after-gate attack can be discovered by monitoring the photocurrent.This paper presents a probabilistic generalization of the attack,which we refer to as probabilistic faint after-gate attack,by introducing probability control modules.Previous countermeasures for photocurrent monitoring may fail in detecting the eavesdropper under some specific probabilities.To mitigate this threat,we provide a method to determine the detectable boundary in the limitation of precision of photocurrent monitoring,and investigate the security of QKD systems under such boundaries using the weak randomness model.
基金This work was supported by the National Key Research and Development Program of China under Grant No.2017YFA0303700the Key Research and Development Program of Guangdong province under Grant No.2018B030325002+1 种基金the National Natural Science Foundation of China under Grant No.11974205Beijing Advanced Innovation Center for Future Chip(ICFC).
文摘Quantum secure direct communication provides a direct means of conveying secret information via quantum states among legitimate users.The past two decades have witnessed its great strides both theoretically and experimentally.However,the security analysis of it still stays in its infant.Some practical problems in this field to be solved urgently,such as detector efficiency mismatch,side-channel effect and source imperfection,are propelling the birth of a more impeccable solution.In this paper,we establish a new framework of the security analysis driven by numerics where all the practical problems may be taken into account naturally.We apply this framework to several variations of the DL04 protocol considering real-world experimental conditions.Also,we propose two optimizing methods to process the numerical part of the framework so as to meet different requirements in practice.With these properties considered,we predict the robust framework would open up a broad avenue of the development in the field.
文摘Quantum key distribution(QKD)guarantees informationtheoretic security through the fundamental principles of quantum mechanics.As its matures,QKD networks have achieved long-distance deployment,showing significant advancements in practical quantum-security communication infrastructure[1].When transitioning to large scale quantum communication networks with complicated topologies,conventional paradigms,which are based on point-to-point QKD links connected by trusted nodes,face technical challenges on achieving scalability and optimizing resource allocation.Quantum entanglements are important resources for quantum networks.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20211145)the Fundamental Research Funds for the Central Universities(020414380182)+1 种基金the Key Research and Development Program of Nanjing Jiangbei New Aera(ZDYD20210101)the Program for Innovative Talents and Entrepreneurs in Jiangsu(JSSCRC2021484)。
文摘The security of quantum key distribution(QKD)is severely threatened by discrepancies between realistic devices and theoretical assumptions.Recently,a significant framework called the reference technique was proposed to provide security against arbitrary source flaws under current technology such as state preparation flaws,side channels caused by mode dependencies,the Trojan horse attacks and pulse correlations.Here,we adopt the reference technique to prove security of an efficient four-phase measurement-device-independent QKD using laser pulses against potential source imperfections.We present a characterization of source flaws and connect them to experiments,together with a finite-key analysis against coherent attacks.In addition,we demonstrate the feasibility of our protocol through a proof-of-principle experimental implementation and achieve a secure key rate of 253 bps with a 20 d B channel loss.Compared with previous QKD protocols with imperfect devices,our study considerably improves both the secure key rate and the transmission distance,and shows application potential in the practical deployment of secure QKD with device imperfections.
