Physical-layer secret key generation(PSKG)provides a lightweight way for group key(GK)sharing between wireless users in large-scale wireless networks.However,most of the existing works in this field consider only grou...Physical-layer secret key generation(PSKG)provides a lightweight way for group key(GK)sharing between wireless users in large-scale wireless networks.However,most of the existing works in this field consider only group communication.For a commonly dual-task scenario,where both GK and pairwise key(PK)are required,traditional methods are less suitable for direct extension.For the first time,we discover a security issue with traditional methods in dual-task scenarios,which has not previously been recognized.We propose an innovative segment-based key generation method to solve this security issue.We do not directly use PK exclusively to negotiate the GK as traditional methods.Instead,we generate GK and PK separately through segmentation which is the first solution to meet dual-task.We also perform security and rate analysis.It is demonstrated that our method is effective in solving this security issue from an information-theoretic perspective.The rate results of simulation are also consistent with the our rate derivation.展开更多
[Objective] This paper aimed to solve the problems existing in commercial layers breeding. [Method] Key points of culture were summarized. [ Result] The timing of purchasing chickenens, comprehensive epidemic preventi...[Objective] This paper aimed to solve the problems existing in commercial layers breeding. [Method] Key points of culture were summarized. [ Result] The timing of purchasing chickenens, comprehensive epidemic prevention, decisively cleaning out predicted low-yield chickenen flock or layers, chickenens quality, control of chickenens＇ breeding skills, sufficient drinking water, feed quality, timely elimination of layer flock, correctly adjusting production rhythm, proper scale and other aspects should be paid attention to. [Condusion] Breeding commercial layers could get significant economic benefits through above measures.展开更多
Due to the broadcast nature of wireless channels and the development of quantum computers,the confidentiality of wireless communication is seriously threatened.In this paper,we propose an integrated communications and...Due to the broadcast nature of wireless channels and the development of quantum computers,the confidentiality of wireless communication is seriously threatened.In this paper,we propose an integrated communications and security(ICAS)design to enhance communication security using reconfigurable intelligent surfaces(RIS),in which the physical layer key generation(PLKG)rate and the data transmission rate are jointly considered.Specifically,to deal with the threat of eavesdropping attackers,we focus on studying the simultaneous transmission and key generation(STAG)by configuring the RIS phase shift.Firstly,we derive the key generation rate of the RIS assisted PLKG and formulate the optimization problem.Then,in light of the dynamic wireless environments,the optimization problem is modeled as a finite Markov decision process.We put forward a policy gradient-based proximal policy optimization(PPO)algorithm to optimize the continuous phase shift of the RIS,which improves the convergence stability and explores the security boundary of the RIS phase shift for STAG.The simulation results demonstrate that the proposed algorithm outperforms the benchmark method in convergence stability and system performance.By reasonably allocating the weight factors for the data transmission rate and the key generation rate,“one-time pad”communication can be achieved.The proposed method has about 90%performance improvement for“one-time pad”communication compared with the benchmark methods.展开更多
Physical layer key generation(PKG)technology leverages the reciprocal channel randomness to generate the shared secret keys.The low secret key capacity of the existing PKG schemes is due to the reduction in degree-of-...Physical layer key generation(PKG)technology leverages the reciprocal channel randomness to generate the shared secret keys.The low secret key capacity of the existing PKG schemes is due to the reduction in degree-of-freedom from multipath fading channels to multipath combined channels.To improve the wireless key generation rate,we propose a multipath channel diversity-based PKG scheme.Assisted by dynamic metasurface antennas(DMA),a two-stage multipath channel parameter estimation algorithm is proposed to efficiently realize super-resolution multipath parameter estimation.The proposed algorithm first estimates the angle of arrival(AOA)based on the reconfigurable radiation pattern of DMA,and then utilizes the results to design the training beamforming and receive beamforming to improve the estimation accuracy of the path gain.After multipath separation and parameter estimation,multi-dimensional independent path gains are utilized for generating secret keys.Finally,we analyze the security and complexity of the proposed scheme and give an upper bound on the secret key capacity in the high signal-to-noise ratio(SNR)region.The simulation results demonstrate that the proposed scheme can greatly improve the secret key capacity compared with the existing schemes.展开更多
A numerical simulation is performed to find out a key vortical structure in the laminar-turbulent transition. A low-speed streak is generated inside a laminar boundary layer using an isolated cuboid roughness, aimed a...A numerical simulation is performed to find out a key vortical structure in the laminar-turbulent transition. A low-speed streak is generated inside a laminar boundary layer using an isolated cuboid roughness, aimed at providing an environment unstable to outer disturbances. Then, a short duration jet is issued into the boundary layer. When the jet velocity is low, some vortices appear in the boundary layer, but the transition of the boundary layer does not take place.However, when the jet velocity exceeds a certain threshold, two vortices newly appear above the elongated legs of a V-shaped vortex and only one of them is stretched and survives. After that,vortices are generated one after another around the survived one. By comparing the decayed and the survived vortices, it is found that the difference in their heights is the key characteristic which leads to the transition.展开更多
Despite the rapid development in Worldwide Interoperability for Microwave Access (WiMAX) technologies,key technologies for the Physical Layer (PHY) still need to be further improved so as to achieve highly efficient a...Despite the rapid development in Worldwide Interoperability for Microwave Access (WiMAX) technologies,key technologies for the Physical Layer (PHY) still need to be further improved so as to achieve highly efficient and reliable communication performance,as well as to support a mobile environment with a higher transmisison rate. As an amendment to IEEE 802.16d (for fixed broadband wireless access systems),IEEE 802.16e (for mobile broadband wireless access systems) introduces the Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) technologies into the PHY,doubling the transmission rate while supporting a certain degree of mobility. In the future,more advanced Air Interface (AI) technology is to be applied in the IEEE 802.16m standard.展开更多
As a smart spectrum sharing technology, Cognitive Radio (CR) is becoming a hot topic in the field of wireless telecommunications. Besides providing traditional services, the cognitive radio network Media Access Contro...As a smart spectrum sharing technology, Cognitive Radio (CR) is becoming a hot topic in the field of wireless telecommunications. Besides providing traditional services, the cognitive radio network Media Access Control (MAC) layer is required to perform an entirely new set of functions for effective reusing spectrum opportunity, without causing any harmful interference to incumbents. Spectrum sensing management selects and optimizes sensing strategies and parameters by the selection of sensing mode, sensing period, sensing time, sensing channel, and sensing quiet period. Access control avoids collision with primary users mainly by cooperation access and transparent access. Dynamic spectrum allocation optimizes the allocation of uncertain spectrum for binary interference model and accumulative interference model. Security mechanism adds authentication and encryption mechanisms to MAC frame to defense MAC layer security attacks. Cross-layer design combines MAC layer information with physical layer or higher layers information, such as network layer, transmission layer, to achieve global optimization.展开更多
Secret key generation(SKG)is a promising solution to the problem of wireless communications security.As the first step of SKG,channel probing affects it significantly.Although there have been some probing schemes,ther...Secret key generation(SKG)is a promising solution to the problem of wireless communications security.As the first step of SKG,channel probing affects it significantly.Although there have been some probing schemes,there is a lack of research on the optimization of the probing process.This study investigates how to optimize correlated parameters to maximize the SKG rate(SKGR)in the time-division duplex(TDD)mode.First,we build a probing model which includes the effects of transmitting power,the probing period,and the dimension of sample vectors.Based on the model,the analytical expression of the SKGR is given.Next,we formulate an optimization problem for maximizing the SKGR and give an algorithm to solve it.We conclude the SKGR monotonically increases as the transmitting power increases.Relevant mathematical proofs are given in this study.From the simulation results,increasing appropriately the probing period and the dimension of the sample vector could increase the SKGR dramatically compared to a yardstick,which indicates the importance of optimizing the parameters related to the channel probing phase.展开更多
With the continuous progress of communication technology,traditional encryption algorithms cannot meet the demands of modern wireless communication security.Secure communication based on physical layer encryption emer...With the continuous progress of communication technology,traditional encryption algorithms cannot meet the demands of modern wireless communication security.Secure communication based on physical layer encryption emerges as a solution.To meet the low Key Disagreement Rate(KDR)and high Key Generation Rate(KGR)requirements for physical layer key generation,this paper proposes two quantization algorithms,Improve-CQG and Interpolate-CQG,based on the Channel Quantization with Guard band(CQG)algorithm.The former divides the characteristic quantization into two phases:threshold filtering and guard band quantization,while the latter adds a step after these two phases:interpolation quantization.Compared to the CQG algorithm,the Improve-CQG algorithm enhances the granularity of filtered quantization values.The core concept of the Interpolate-CQG algorithm is to utilize threshold filtering and the rounded-off quantization values from the guard band quantization phase.The symbol information corresponding to these index values is replaced by a new interpolated symbol and inserted into the key by the agreed quantized coordinates.Simulation proves that the Interpolate-CQG is an effective quantization algorithm for the key generation with lower KDR and higher KGR than the Improve-CQA and Improve-CQG.展开更多
This paper proposes a lightweight traffic sign detection system based on you only look once(YOLO).Firstly,the classification to fusion(C2f)structure is integrated into the backbone network,employing deformable convolu...This paper proposes a lightweight traffic sign detection system based on you only look once(YOLO).Firstly,the classification to fusion(C2f)structure is integrated into the backbone network,employing deformable convolution and bi-directional feature pyramid network(BiFPN)_Concat to improve the adaptability of the network.Secondly,the simple attention module(SimAm)is embedded to prioritize key features and reduce the complexity of the model after the C2f layer at the end of the backbone network.Next,the focal efficient intersection over union(EloU)is introduced to adjust the weights of challenging samples.Finally,we accomplish the design and deployment for the mobile app.The results demonstrate improvements,with the F1 score of 0.8987,mean average precision(mAP)@0.5 of 98.8%,mAP@0.5:0.95 of 75.6%,and the detection speed of 50 frames per second(FPS).展开更多
The open and broadcast nature of wireless channels leads to the inherent security problem of information leakage in wireless communication.We can utilize endogenous security functions to resolve this problem.The funda...The open and broadcast nature of wireless channels leads to the inherent security problem of information leakage in wireless communication.We can utilize endogenous security functions to resolve this problem.The fundamental solution is channel-based mechanisms,like physical layer secret keys.Unfortunately,current investigations have not fully exploited the randomness of wireless channels,making secret key rates not high.Consequently,user data can be encrypted by reducing the data rate to match the secret key rate.Based on the analysis of the endogenous wireless security principle,we proposed that the channel-based endogenous secret key rate can nearly match the maximum data rate in the fast-fading environments.After that,we validated the proposition in an instantiation system with multiple phase shift keying(MPSK)inputs from the perspectives of both theoretical analysis and simulation experiments.The results indicate that it is possible to accomplish the onetime pad without decreasing the data rate via channelbased endogenous keys.Besides,we can realize highspeed endogenously secure transmission by introducing independent channels in the domains of frequency,space,or time.The conclusions derived provide a new idea for wireless security and promote the application of the endogenous security theory.展开更多
In static or quasi-static wireless channel environments, secret key generation(SKG) based on wireless channels is vulnerable to active attacks due to the openness and invariance of public pilot, especially man-inthe-m...In static or quasi-static wireless channel environments, secret key generation(SKG) based on wireless channels is vulnerable to active attacks due to the openness and invariance of public pilot, especially man-inthe-middle(MITM) attacks, where attacker acts as a transparent relay to manipulate channel measurements and derive the generated keys. In order to fight against this attack, a dynamic private pilot is designed, where both private pilot and secret key are derived from the characteristics of wireless channels and private to third party. In static or quasi-static environments, we use singular value decomposition techniques to reconstitute the wireless channels to improve the randomness of the wireless channels. Private pilot can encrypt and authenticate the wireless channels, which can make channel state information intercepted by MITM attacker reduced to zero and the SKG rate close to that without attacks. Results of analysis and simulation show the proposed SKG scheme can withdraw the MITM attacks.展开更多
A novel secret key generation(SKG)method based on two-way randomness is proposed for TDD-SISO system.The legitimate transceivers mutually transmit their own random signal via reciprocal wireless channel,then the multi...A novel secret key generation(SKG)method based on two-way randomness is proposed for TDD-SISO system.The legitimate transceivers mutually transmit their own random signal via reciprocal wireless channel,then the multiplication of transmitted and received signal is used as common randomness to generate secret keys.In quasi-static channel,the theoretical SKG rates(SKGRs)of the three SKG methods,namely wireless channel based,one-way randomness and two-way randomness,are derived and compared.Further,two practical SKG schemes based on twoway randomness,Scheme-1bit and Scheme-3bit,are completely designed and simulated.Generally,Scheme-1bit applies to low signal to noise ratio(SNR)scenarios and achieves 0.13~0.86bit/T_s SKGR and 10^(-2)~10^(-5) level secret key outage probability(SKOP),while Scheme-3bit fits high SNR situation and obtains 0.93~1.35bit/T_s SKGR and 10^(-3)~10^(-4) level SKOP.At last,the national institute of standards and technology(NIST)test is conducted to evaluate the secret key randomness(SKRD)and the test results show that both of the proposed schemes have passed the test.展开更多
Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wirele...Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’uncertainty.However,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power allocation.The coherence time for PHY-SKG is not applicable to secure wireless channels.This is because coherence time is for a certain period of time.Thus,legitimate users generate the secret keys(SKs)with a shorter key length in size.Hence,an attacker can quickly get information about the SKs.Consequently,the attacker can easily get valuable information from authentic users.Therefore,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate users.Hence,we propose an alternative method,i.e.,a power allocation,to improve the SKGR.Our results show 72%higher SKGR in bits/sec by increasing power transmission.In addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission equations.We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR.The SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=1.The value of SKGR is reduced to 18.5%at 250 mW when epsilonis 0.5.Furthermore,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=0.5.Hence,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.展开更多
A security architecture using secret key algorithm and vertical authentication mode is proposed. Establish security protocols in the chip of smart key at network client or mobile phone, and establish key exchange prot...A security architecture using secret key algorithm and vertical authentication mode is proposed. Establish security protocols in the chip of smart key at network client or mobile phone, and establish key exchange protocol in the chip of encryption cards at network key management center. A combined key real-time generation algorithm is used to solve the update and management problems. Online or offline authentication and documents encryption transmission protocols are adopted to achieve credible connection between users. Accordingly, set up security layer over Internet, which provides convenient encryption ability to each network user, and build credible and secure network system.展开更多
As cyber threats keep changing and business environments adapt, a comprehensive approach to disaster recovery involves more than just defensive measures. This research delves deep into the strategies required to respo...As cyber threats keep changing and business environments adapt, a comprehensive approach to disaster recovery involves more than just defensive measures. This research delves deep into the strategies required to respond to threats and anticipate and mitigate them proactively. Beginning with understanding the critical need for a layered defense and the intricacies of the attacker’s journey, the research offers insights into specialized defense techniques, emphasizing the importance of timely and strategic responses during incidents. Risk management is brought to the forefront, underscoring businesses’ need to adopt mature risk assessment practices and understand the potential risk impact areas. Additionally, the value of threat intelligence is explored, shedding light on the importance of active engagement within sharing communities and the vigilant observation of adversary motivations. “Beyond Defense: Proactive Approaches to Disaster Recovery and Threat Intelligence in Modern Enterprises” is a comprehensive guide for organizations aiming to fortify their cybersecurity posture, marrying best practices in proactive and reactive measures in the ever-challenging digital realm.展开更多
In quasi-static wireless channel scenarios,the generation of physical layer keys faces the challenge of invariant spatial and temporal channel characteristics,resulting in a high key disagreement rate(KDR)and low key ...In quasi-static wireless channel scenarios,the generation of physical layer keys faces the challenge of invariant spatial and temporal channel characteristics,resulting in a high key disagreement rate(KDR)and low key generation rate(KGR).To address these issues,we propose a novel reconfigurable intelligent surface(RIS)-aided secret key generation approach using an autoencoder and K-means quantization algorithm.The proposed method uses channel state information(CSI)for channel estimation and dynamically adjusts the refection coeficients of the RIS to create a rapidly fuctuating channel.This strategy enables the extraction of dynamic channel parameters,thereby enhancing channel randomness.Additionally,by integrating the autoencoder with the K-means clustering quantization algorithm,the method eficiently extracts random bits from complex,ambiguous,and high-dimensional channel parameters,significantly reducing KDR.Simulations demonstrate that,under various signal-to-noise ratios(SNRs),the proposed method performs excellently in terms of KGR and KDR.Furthermore,the randomness of the generated keys is validated through the National Institute of Standards and Technology(NIST)test suite.展开更多
Fog computing paradigm extends computing,communication,storage,and network resources to the network’s edge.As the fog layer is located between cloud and end-users,it can provide more convenience and timely services t...Fog computing paradigm extends computing,communication,storage,and network resources to the network’s edge.As the fog layer is located between cloud and end-users,it can provide more convenience and timely services to end-users.However,in fog computing(FC),attackers can behave as real fog nodes or end-users to provide malicious services in the network.The attacker acts as an impersonator to impersonate other legitimate users.Therefore,in this work,we present a detection technique to secure the FC environment.First,we model a physical layer key generation based on wireless channel characteristics.To generate the secret keys between the legitimate users and avoid impersonators,we then consider a Double Sarsa technique to identify the impersonators at the receiver end.We compare our proposed Double Sarsa technique with the other two methods to validate our work,i.e.,Sarsa and Q-learning.The simulation results demonstrate that the method based on Double Sarsa outperforms Sarsa and Q-learning approaches in terms of false alarm rate(FAR),miss detection rate(MDR),and average error rate(AER).展开更多
Remarkable progress has been made in satellite-based quantum key distribution [QKD],which can effectively provide QKD service even at the intercontinental scale and construct an ultralong-distance global quantum netwo...Remarkable progress has been made in satellite-based quantum key distribution [QKD],which can effectively provide QKD service even at the intercontinental scale and construct an ultralong-distance global quantum network.But there are still some places where terrestrial fiber and ground stations cannot be constructed,like harsh mountainous areas and air space above the sea.So the airborne platform is expected to replace the ground station and provide flexible and relay links for the large-scale integrated communication network.However,the photon transmission rate would be randomly reduced,owing to the randomly distributed boundary layer that surrounds the surface of the aircraft when the flight speed is larger than0.3 Ma.Previous research of airborne QKD with boundary layer effects is mainly under the air-to-ground scenario in which the aircraft is a transmitter,while the satellite-to-aircraft scenario is rarely reported.In this article,we propose a performance evaluation scheme of satellite-to-aircraft QKD with boundary layer effects in which the aircraft is the receiver.With common experimental settings,the boundary layer would introduce a ~31 dB loss to the transmitted photons,decrease ~47% of the quantum communication time,and decrease ~51% of the secure key rate,which shows that the aero-optical effects caused by the boundary layer cannot be ignored.Our study can be performed in future airborne quantum communication designs.展开更多
To secure the wireless connection between devices with low computational power has been a challenging problem due to heterogeneity in operating devices,device to device communication in Internet of Things(IoTs)and 5G ...To secure the wireless connection between devices with low computational power has been a challenging problem due to heterogeneity in operating devices,device to device communication in Internet of Things(IoTs)and 5G wireless systems.Physical layer key generation(PLKG)tackles this secrecy problem by introducing private keys among two connecting devices through wireless medium.In this paper,relative calibration is used as a method to enhance channel reciprocity which in turn increases the performance of the key generation process.Channel reciprocity based key generation is emerged as better PLKG methodology to obtain secure wireless connection in IoTs and 5G systems.Circulant deconvolution is proposed as a promising technique for relative calibration to ensure channel reciprocity in comparison to existing techniques Total Least Square(TLS)and Structured Total Least Square(STLS).The proposed deconvolution technique replicates the performance of the STLS by exploiting the possibility of higher information reuse and its lesser computational complexity leads to less processing time in comparison to the STLS.The presented idea is validated by observing the relation between signalto-noise ratio(SNR)and the correlation coefficient of the corresponding channel measurements between communicating parties.展开更多
基金supported in part by the National Key R&D Program of China(No.2022YFB2902202)in part by the Fundamental Research Funds for the Central Universities(No.2242023K30034)+2 种基金in part by the National Natural Science Foundation of China(No.62171121,U22A2001),in part by the National Natural Science Foundation of China(No.62301144)in part by the National Natural Science Foundation of Jiangsu Province,China(No.BK20211160)in part by the Southeast University Startup Fund(No.4009012301)。
文摘Physical-layer secret key generation(PSKG)provides a lightweight way for group key(GK)sharing between wireless users in large-scale wireless networks.However,most of the existing works in this field consider only group communication.For a commonly dual-task scenario,where both GK and pairwise key(PK)are required,traditional methods are less suitable for direct extension.For the first time,we discover a security issue with traditional methods in dual-task scenarios,which has not previously been recognized.We propose an innovative segment-based key generation method to solve this security issue.We do not directly use PK exclusively to negotiate the GK as traditional methods.Instead,we generate GK and PK separately through segmentation which is the first solution to meet dual-task.We also perform security and rate analysis.It is demonstrated that our method is effective in solving this security issue from an information-theoretic perspective.The rate results of simulation are also consistent with the our rate derivation.
基金supported by Qinhuangdao Science&Technology Support Program
文摘[Objective] This paper aimed to solve the problems existing in commercial layers breeding. [Method] Key points of culture were summarized. [ Result] The timing of purchasing chickenens, comprehensive epidemic prevention, decisively cleaning out predicted low-yield chickenen flock or layers, chickenens quality, control of chickenens＇ breeding skills, sufficient drinking water, feed quality, timely elimination of layer flock, correctly adjusting production rhythm, proper scale and other aspects should be paid attention to. [Condusion] Breeding commercial layers could get significant economic benefits through above measures.
基金supported in part by the National Science Foundation of China(NSFC)under Grant No.62371131in part by the National Key R&D Program of China under Grant No.2024YFE0200700in part by the program of Zhishan Young Scholar of Southeast University under Grant No.2242024RCB0030。
文摘Due to the broadcast nature of wireless channels and the development of quantum computers,the confidentiality of wireless communication is seriously threatened.In this paper,we propose an integrated communications and security(ICAS)design to enhance communication security using reconfigurable intelligent surfaces(RIS),in which the physical layer key generation(PLKG)rate and the data transmission rate are jointly considered.Specifically,to deal with the threat of eavesdropping attackers,we focus on studying the simultaneous transmission and key generation(STAG)by configuring the RIS phase shift.Firstly,we derive the key generation rate of the RIS assisted PLKG and formulate the optimization problem.Then,in light of the dynamic wireless environments,the optimization problem is modeled as a finite Markov decision process.We put forward a policy gradient-based proximal policy optimization(PPO)algorithm to optimize the continuous phase shift of the RIS,which improves the convergence stability and explores the security boundary of the RIS phase shift for STAG.The simulation results demonstrate that the proposed algorithm outperforms the benchmark method in convergence stability and system performance.By reasonably allocating the weight factors for the data transmission rate and the key generation rate,“one-time pad”communication can be achieved.The proposed method has about 90%performance improvement for“one-time pad”communication compared with the benchmark methods.
基金supported in part by the National Natural Science Foundation of China(No.U22A2001)the National Key Research and Development Program of China(No.2022YFB2902202,No.2022YFB2902205)。
文摘Physical layer key generation(PKG)technology leverages the reciprocal channel randomness to generate the shared secret keys.The low secret key capacity of the existing PKG schemes is due to the reduction in degree-of-freedom from multipath fading channels to multipath combined channels.To improve the wireless key generation rate,we propose a multipath channel diversity-based PKG scheme.Assisted by dynamic metasurface antennas(DMA),a two-stage multipath channel parameter estimation algorithm is proposed to efficiently realize super-resolution multipath parameter estimation.The proposed algorithm first estimates the angle of arrival(AOA)based on the reconfigurable radiation pattern of DMA,and then utilizes the results to design the training beamforming and receive beamforming to improve the estimation accuracy of the path gain.After multipath separation and parameter estimation,multi-dimensional independent path gains are utilized for generating secret keys.Finally,we analyze the security and complexity of the proposed scheme and give an upper bound on the secret key capacity in the high signal-to-noise ratio(SNR)region.The simulation results demonstrate that the proposed scheme can greatly improve the secret key capacity compared with the existing schemes.
文摘A numerical simulation is performed to find out a key vortical structure in the laminar-turbulent transition. A low-speed streak is generated inside a laminar boundary layer using an isolated cuboid roughness, aimed at providing an environment unstable to outer disturbances. Then, a short duration jet is issued into the boundary layer. When the jet velocity is low, some vortices appear in the boundary layer, but the transition of the boundary layer does not take place.However, when the jet velocity exceeds a certain threshold, two vortices newly appear above the elongated legs of a V-shaped vortex and only one of them is stretched and survives. After that,vortices are generated one after another around the survived one. By comparing the decayed and the survived vortices, it is found that the difference in their heights is the key characteristic which leads to the transition.
文摘Despite the rapid development in Worldwide Interoperability for Microwave Access (WiMAX) technologies,key technologies for the Physical Layer (PHY) still need to be further improved so as to achieve highly efficient and reliable communication performance,as well as to support a mobile environment with a higher transmisison rate. As an amendment to IEEE 802.16d (for fixed broadband wireless access systems),IEEE 802.16e (for mobile broadband wireless access systems) introduces the Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) technologies into the PHY,doubling the transmission rate while supporting a certain degree of mobility. In the future,more advanced Air Interface (AI) technology is to be applied in the IEEE 802.16m standard.
基金supported by the National Natural Science Foundation of China under Grant No.60772110.
文摘As a smart spectrum sharing technology, Cognitive Radio (CR) is becoming a hot topic in the field of wireless telecommunications. Besides providing traditional services, the cognitive radio network Media Access Control (MAC) layer is required to perform an entirely new set of functions for effective reusing spectrum opportunity, without causing any harmful interference to incumbents. Spectrum sensing management selects and optimizes sensing strategies and parameters by the selection of sensing mode, sensing period, sensing time, sensing channel, and sensing quiet period. Access control avoids collision with primary users mainly by cooperation access and transparent access. Dynamic spectrum allocation optimizes the allocation of uncertain spectrum for binary interference model and accumulative interference model. Security mechanism adds authentication and encryption mechanisms to MAC frame to defense MAC layer security attacks. Cross-layer design combines MAC layer information with physical layer or higher layers information, such as network layer, transmission layer, to achieve global optimization.
基金supported in part by the national natural science foundation of China (NSFC) under Grant61871193in part by the R&D Program of key science and technology fields in Guangdong province under Grant 2019B090912001in part by the Guangzhou Key Field R&D Program under Grant 202206030005
文摘Secret key generation(SKG)is a promising solution to the problem of wireless communications security.As the first step of SKG,channel probing affects it significantly.Although there have been some probing schemes,there is a lack of research on the optimization of the probing process.This study investigates how to optimize correlated parameters to maximize the SKG rate(SKGR)in the time-division duplex(TDD)mode.First,we build a probing model which includes the effects of transmitting power,the probing period,and the dimension of sample vectors.Based on the model,the analytical expression of the SKGR is given.Next,we formulate an optimization problem for maximizing the SKGR and give an algorithm to solve it.We conclude the SKGR monotonically increases as the transmitting power increases.Relevant mathematical proofs are given in this study.From the simulation results,increasing appropriately the probing period and the dimension of the sample vector could increase the SKGR dramatically compared to a yardstick,which indicates the importance of optimizing the parameters related to the channel probing phase.
基金supported by the National Key Research and Development Program of China(No.2017YFE0135700)the High Level Talent Support Project of Hebei Province(No.A20190301).
文摘With the continuous progress of communication technology,traditional encryption algorithms cannot meet the demands of modern wireless communication security.Secure communication based on physical layer encryption emerges as a solution.To meet the low Key Disagreement Rate(KDR)and high Key Generation Rate(KGR)requirements for physical layer key generation,this paper proposes two quantization algorithms,Improve-CQG and Interpolate-CQG,based on the Channel Quantization with Guard band(CQG)algorithm.The former divides the characteristic quantization into two phases:threshold filtering and guard band quantization,while the latter adds a step after these two phases:interpolation quantization.Compared to the CQG algorithm,the Improve-CQG algorithm enhances the granularity of filtered quantization values.The core concept of the Interpolate-CQG algorithm is to utilize threshold filtering and the rounded-off quantization values from the guard band quantization phase.The symbol information corresponding to these index values is replaced by a new interpolated symbol and inserted into the key by the agreed quantized coordinates.Simulation proves that the Interpolate-CQG is an effective quantization algorithm for the key generation with lower KDR and higher KGR than the Improve-CQA and Improve-CQG.
基金supported by the Shanxi Agricultural University Science and Technology Innovation Enhancement Project。
文摘This paper proposes a lightweight traffic sign detection system based on you only look once(YOLO).Firstly,the classification to fusion(C2f)structure is integrated into the backbone network,employing deformable convolution and bi-directional feature pyramid network(BiFPN)_Concat to improve the adaptability of the network.Secondly,the simple attention module(SimAm)is embedded to prioritize key features and reduce the complexity of the model after the C2f layer at the end of the backbone network.Next,the focal efficient intersection over union(EloU)is introduced to adjust the weights of challenging samples.Finally,we accomplish the design and deployment for the mobile app.The results demonstrate improvements,with the F1 score of 0.8987,mean average precision(mAP)@0.5 of 98.8%,mAP@0.5:0.95 of 75.6%,and the detection speed of 50 frames per second(FPS).
基金funded by the National Key R&D Program of China under Grant 2017YFB0801903the National Natural Science Foundation of China under Grant 61871404,61701538,61521003Doctoral Fund of Ministry of Education of China under Grant 2019M663994。
文摘The open and broadcast nature of wireless channels leads to the inherent security problem of information leakage in wireless communication.We can utilize endogenous security functions to resolve this problem.The fundamental solution is channel-based mechanisms,like physical layer secret keys.Unfortunately,current investigations have not fully exploited the randomness of wireless channels,making secret key rates not high.Consequently,user data can be encrypted by reducing the data rate to match the secret key rate.Based on the analysis of the endogenous wireless security principle,we proposed that the channel-based endogenous secret key rate can nearly match the maximum data rate in the fast-fading environments.After that,we validated the proposition in an instantiation system with multiple phase shift keying(MPSK)inputs from the perspectives of both theoretical analysis and simulation experiments.The results indicate that it is possible to accomplish the onetime pad without decreasing the data rate via channelbased endogenous keys.Besides,we can realize highspeed endogenously secure transmission by introducing independent channels in the domains of frequency,space,or time.The conclusions derived provide a new idea for wireless security and promote the application of the endogenous security theory.
基金supported in part by National Natural Science Foundation of China under Grants No.61601514, 61401510, 61379006Project funded by China Postdoctoral Science Foundation: 2016M592990
文摘In static or quasi-static wireless channel environments, secret key generation(SKG) based on wireless channels is vulnerable to active attacks due to the openness and invariance of public pilot, especially man-inthe-middle(MITM) attacks, where attacker acts as a transparent relay to manipulate channel measurements and derive the generated keys. In order to fight against this attack, a dynamic private pilot is designed, where both private pilot and secret key are derived from the characteristics of wireless channels and private to third party. In static or quasi-static environments, we use singular value decomposition techniques to reconstitute the wireless channels to improve the randomness of the wireless channels. Private pilot can encrypt and authenticate the wireless channels, which can make channel state information intercepted by MITM attacker reduced to zero and the SKG rate close to that without attacks. Results of analysis and simulation show the proposed SKG scheme can withdraw the MITM attacks.
基金supported by National Natural Science Foundation of China(61521003,61501516,61471396,61401510)Postdoctoral Science Foundation of China(2016M592990)
文摘A novel secret key generation(SKG)method based on two-way randomness is proposed for TDD-SISO system.The legitimate transceivers mutually transmit their own random signal via reciprocal wireless channel,then the multiplication of transmitted and received signal is used as common randomness to generate secret keys.In quasi-static channel,the theoretical SKG rates(SKGRs)of the three SKG methods,namely wireless channel based,one-way randomness and two-way randomness,are derived and compared.Further,two practical SKG schemes based on twoway randomness,Scheme-1bit and Scheme-3bit,are completely designed and simulated.Generally,Scheme-1bit applies to low signal to noise ratio(SNR)scenarios and achieves 0.13~0.86bit/T_s SKGR and 10^(-2)~10^(-5) level secret key outage probability(SKOP),while Scheme-3bit fits high SNR situation and obtains 0.93~1.35bit/T_s SKGR and 10^(-3)~10^(-4) level SKOP.At last,the national institute of standards and technology(NIST)test is conducted to evaluate the secret key randomness(SKRD)and the test results show that both of the proposed schemes have passed the test.
基金supported by the China National Key R&D Program(No.2018YFB0803600)Natural Science Foundation of China(No.61801008)+3 种基金Scientific Research Common Program of Beijing Municipal Education Commission(No.KM201910005025)the Chinese Postdoctoral Science Foundation(No.2020M670074)Key Project of Hunan Provincial,Department of Education(No.26420A205)The Construct Program of Applied Characteristics Discipline in Hunan University of Science and Engineering.
文摘Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’uncertainty.However,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power allocation.The coherence time for PHY-SKG is not applicable to secure wireless channels.This is because coherence time is for a certain period of time.Thus,legitimate users generate the secret keys(SKs)with a shorter key length in size.Hence,an attacker can quickly get information about the SKs.Consequently,the attacker can easily get valuable information from authentic users.Therefore,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate users.Hence,we propose an alternative method,i.e.,a power allocation,to improve the SKGR.Our results show 72%higher SKGR in bits/sec by increasing power transmission.In addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission equations.We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR.The SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=1.The value of SKGR is reduced to 18.5%at 250 mW when epsilonis 0.5.Furthermore,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=0.5.Hence,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.
文摘A security architecture using secret key algorithm and vertical authentication mode is proposed. Establish security protocols in the chip of smart key at network client or mobile phone, and establish key exchange protocol in the chip of encryption cards at network key management center. A combined key real-time generation algorithm is used to solve the update and management problems. Online or offline authentication and documents encryption transmission protocols are adopted to achieve credible connection between users. Accordingly, set up security layer over Internet, which provides convenient encryption ability to each network user, and build credible and secure network system.
文摘As cyber threats keep changing and business environments adapt, a comprehensive approach to disaster recovery involves more than just defensive measures. This research delves deep into the strategies required to respond to threats and anticipate and mitigate them proactively. Beginning with understanding the critical need for a layered defense and the intricacies of the attacker’s journey, the research offers insights into specialized defense techniques, emphasizing the importance of timely and strategic responses during incidents. Risk management is brought to the forefront, underscoring businesses’ need to adopt mature risk assessment practices and understand the potential risk impact areas. Additionally, the value of threat intelligence is explored, shedding light on the importance of active engagement within sharing communities and the vigilant observation of adversary motivations. “Beyond Defense: Proactive Approaches to Disaster Recovery and Threat Intelligence in Modern Enterprises” is a comprehensive guide for organizations aiming to fortify their cybersecurity posture, marrying best practices in proactive and reactive measures in the ever-challenging digital realm.
基金Project supported by the National Natural Science Foundation of China(No.62361010)the Cultivation Project of Guizhou University(No.[2019]56)the Major Scientific and Technological Special Project of Guizhou Province(No.[2024]014)。
文摘In quasi-static wireless channel scenarios,the generation of physical layer keys faces the challenge of invariant spatial and temporal channel characteristics,resulting in a high key disagreement rate(KDR)and low key generation rate(KGR).To address these issues,we propose a novel reconfigurable intelligent surface(RIS)-aided secret key generation approach using an autoencoder and K-means quantization algorithm.The proposed method uses channel state information(CSI)for channel estimation and dynamically adjusts the refection coeficients of the RIS to create a rapidly fuctuating channel.This strategy enables the extraction of dynamic channel parameters,thereby enhancing channel randomness.Additionally,by integrating the autoencoder with the K-means clustering quantization algorithm,the method eficiently extracts random bits from complex,ambiguous,and high-dimensional channel parameters,significantly reducing KDR.Simulations demonstrate that,under various signal-to-noise ratios(SNRs),the proposed method performs excellently in terms of KGR and KDR.Furthermore,the randomness of the generated keys is validated through the National Institute of Standards and Technology(NIST)test suite.
基金supported by Natural Science Foundation of China(61801008)The China National Key R&D Program(No.2018YFB0803600)+1 种基金Scientific Research Common Program of Beijing Municipal Commission of Education(No.KM201910005025)Chinese Postdoctoral Science Foundation(No.2020M670074).
文摘Fog computing paradigm extends computing,communication,storage,and network resources to the network’s edge.As the fog layer is located between cloud and end-users,it can provide more convenience and timely services to end-users.However,in fog computing(FC),attackers can behave as real fog nodes or end-users to provide malicious services in the network.The attacker acts as an impersonator to impersonate other legitimate users.Therefore,in this work,we present a detection technique to secure the FC environment.First,we model a physical layer key generation based on wireless channel characteristics.To generate the secret keys between the legitimate users and avoid impersonators,we then consider a Double Sarsa technique to identify the impersonators at the receiver end.We compare our proposed Double Sarsa technique with the other two methods to validate our work,i.e.,Sarsa and Q-learning.The simulation results demonstrate that the method based on Double Sarsa outperforms Sarsa and Q-learning approaches in terms of false alarm rate(FAR),miss detection rate(MDR),and average error rate(AER).
基金supported by the National Natural Science Foundation of China(Nos.61971436,61972410,and 61803382)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2018020JQ6020)+1 种基金the Research Plan of National University of Defense Technology(Nos.ZK19-13 and 19-QNCXJ-107)the Postgraduate Scientific Research Innovation Project of Hunan Province(No.CX20200003)。
文摘Remarkable progress has been made in satellite-based quantum key distribution [QKD],which can effectively provide QKD service even at the intercontinental scale and construct an ultralong-distance global quantum network.But there are still some places where terrestrial fiber and ground stations cannot be constructed,like harsh mountainous areas and air space above the sea.So the airborne platform is expected to replace the ground station and provide flexible and relay links for the large-scale integrated communication network.However,the photon transmission rate would be randomly reduced,owing to the randomly distributed boundary layer that surrounds the surface of the aircraft when the flight speed is larger than0.3 Ma.Previous research of airborne QKD with boundary layer effects is mainly under the air-to-ground scenario in which the aircraft is a transmitter,while the satellite-to-aircraft scenario is rarely reported.In this article,we propose a performance evaluation scheme of satellite-to-aircraft QKD with boundary layer effects in which the aircraft is the receiver.With common experimental settings,the boundary layer would introduce a ~31 dB loss to the transmitted photons,decrease ~47% of the quantum communication time,and decrease ~51% of the secure key rate,which shows that the aero-optical effects caused by the boundary layer cannot be ignored.Our study can be performed in future airborne quantum communication designs.
文摘To secure the wireless connection between devices with low computational power has been a challenging problem due to heterogeneity in operating devices,device to device communication in Internet of Things(IoTs)and 5G wireless systems.Physical layer key generation(PLKG)tackles this secrecy problem by introducing private keys among two connecting devices through wireless medium.In this paper,relative calibration is used as a method to enhance channel reciprocity which in turn increases the performance of the key generation process.Channel reciprocity based key generation is emerged as better PLKG methodology to obtain secure wireless connection in IoTs and 5G systems.Circulant deconvolution is proposed as a promising technique for relative calibration to ensure channel reciprocity in comparison to existing techniques Total Least Square(TLS)and Structured Total Least Square(STLS).The proposed deconvolution technique replicates the performance of the STLS by exploiting the possibility of higher information reuse and its lesser computational complexity leads to less processing time in comparison to the STLS.The presented idea is validated by observing the relation between signalto-noise ratio(SNR)and the correlation coefficient of the corresponding channel measurements between communicating parties.
