Wireless sensor networks (WSNs) have many potential applications [1,2] and unique challenges. They usually consist of hundreds or thousands of small sensor nodes such as MICA2, which operate autonomously;conditions su...Wireless sensor networks (WSNs) have many potential applications [1,2] and unique challenges. They usually consist of hundreds or thousands of small sensor nodes such as MICA2, which operate autonomously;conditions such as cost, invisible deployment and many application domains, lead to small size and resource limited sensors [3]. WSNs are susceptible to many types of link layer attacks [1] and most of traditional network security techniques are unusable on WSNs [3];This is due to wireless and shared nature of communication channel, untrusted transmissions, deployment in open environments, unattended nature and limited resources [1]. Therefore security is a vital requirement for these networks;but we have to design a proper security mechanism that attends to WSN’s constraints and requirements. In this paper, we focus on security of WSNs, divide it (the WSNs security) into four categories and will consider them, include: an overview of WSNs, security in WSNs, the threat model on WSNs, a wide variety of WSNs’ link layer attacks and a comparison of them. This work enables us to identify the purpose and capabilities of the attackers;furthermore, the goal and effects of the link layer attacks on WSNs are introduced. Also, this paper discusses known approaches of security detection and defensive mechanisms against the link layer attacks;this would enable IT security managers to manage the link layer attacks of WSNs more effectively.展开更多
With the rapid development of the Internet of Things(IoT),wireless technology has become an indispensable part of modern computing platforms and embedded systems.Wireless device fingerprint identification is deemed as...With the rapid development of the Internet of Things(IoT),wireless technology has become an indispensable part of modern computing platforms and embedded systems.Wireless device fingerprint identification is deemed as a promising solution towards enhancing the security of device access authentication and communication process in the IoT scenario.However,the extraction of features from the network layer and its upper layers often confront restrictions from specific devices:the association with a certain wireless network and the access to the plaintext of the payload.Meanwhile,Bluetooth Low Energy(BLE)packets have been encrypted above the link layer,which makes those features difficult to extract.To tackle these problems,we introduce a novel method to identify BLE devices based on the fingerprint features in the data link layer.Initially,the BLE packets are collected through a receiver based on software-defined radio technology.Then,fields that reflect device differences in BLE broadcast packets are extracted through traffic analysis.Finally,a MultiLayer Perceptron(MLP)model is employed to recognize the category of BLE devices.An experimental result on a dataset with 15 types of BLE devices shows that the identification accuracy of the proposed method can reach 99.8%,which accomplishes better performance over previous work.展开更多
As an important scheme of future global mobile satellite communication systems to provide multimedia service, a Double-Layer Satellite Network （DLSN） with MEO satellites and LEO satellites is proposed. The Inter-Orb...As an important scheme of future global mobile satellite communication systems to provide multimedia service, a Double-Layer Satellite Network （DLSN） with MEO satellites and LEO satellites is proposed. The Inter-Orbit-Links （IOLs） between layers is an essential factor, which affects the performances of the DLSN systems. Considering certain constellation parameters, the geometric characteristics of IOLs are described and the connectivity of MEO satellites and LEO satellites in the DLSN is analyzed. By computer simulation, the results show that IOLs should be selectively established according to certain parameters rather than the simple in-sight principle.展开更多
Multilayer film was fabricated on an electrode surface by alternate layer-by-layer（LBL） adsorption of polycationic redox polymer（PEI-Fc） and dye-linked L-proline dehydrogenase（L-proDH）.The electrochemistry of th...Multilayer film was fabricated on an electrode surface by alternate layer-by-layer（LBL） adsorption of polycationic redox polymer（PEI-Fc） and dye-linked L-proline dehydrogenase（L-proDH）.The electrochemistry of the PEI-Fc/L-proDH multilayer modified electrode was investigated by cyclic voltammetry,and the enzyme catalysis mediated by the redox polymer was studied in a solution containing L-proline.It was observed that electron communication between L-proDH and the electrode was achieved with the help of PEI-Fc.A mathematical expression for the current response was evaluated based on the Michaelis-Menten kinetics mode,and the calculated currents fitted well with the experimental data.The kinetic analysis indicates that only a small fraction of the immobilized enzyme was efficiently electrically wired by the redox polymer.展开更多
文摘Wireless sensor networks (WSNs) have many potential applications [1,2] and unique challenges. They usually consist of hundreds or thousands of small sensor nodes such as MICA2, which operate autonomously;conditions such as cost, invisible deployment and many application domains, lead to small size and resource limited sensors [3]. WSNs are susceptible to many types of link layer attacks [1] and most of traditional network security techniques are unusable on WSNs [3];This is due to wireless and shared nature of communication channel, untrusted transmissions, deployment in open environments, unattended nature and limited resources [1]. Therefore security is a vital requirement for these networks;but we have to design a proper security mechanism that attends to WSN’s constraints and requirements. In this paper, we focus on security of WSNs, divide it (the WSNs security) into four categories and will consider them, include: an overview of WSNs, security in WSNs, the threat model on WSNs, a wide variety of WSNs’ link layer attacks and a comparison of them. This work enables us to identify the purpose and capabilities of the attackers;furthermore, the goal and effects of the link layer attacks on WSNs are introduced. Also, this paper discusses known approaches of security detection and defensive mechanisms against the link layer attacks;this would enable IT security managers to manage the link layer attacks of WSNs more effectively.
基金supported by the National Natural Science Foundation of China(Nos.61972085,62072103,62232004)the Jiangsu Provincial Key R&D Program(Nos.BE2021729,BE2022680,BE2022065-4)+3 种基金the Jiangsu Provincial Key Laboratory of Network and Information Security(No.BM2003201)the Key Laboratory of Computer Network and Information Integration of Ministry of Education of China(No.93K-9)the Collaborative Innovation Center of Novel Software Technology and Industrialization,the Fundamental Research Funds for the Central Universities,the CCF-Baidu Open Fund(No.2021PP15002000)the Future Network Scientific Research Fund Project(No.FNSRFP-2021-YB-02).
文摘With the rapid development of the Internet of Things(IoT),wireless technology has become an indispensable part of modern computing platforms and embedded systems.Wireless device fingerprint identification is deemed as a promising solution towards enhancing the security of device access authentication and communication process in the IoT scenario.However,the extraction of features from the network layer and its upper layers often confront restrictions from specific devices:the association with a certain wireless network and the access to the plaintext of the payload.Meanwhile,Bluetooth Low Energy(BLE)packets have been encrypted above the link layer,which makes those features difficult to extract.To tackle these problems,we introduce a novel method to identify BLE devices based on the fingerprint features in the data link layer.Initially,the BLE packets are collected through a receiver based on software-defined radio technology.Then,fields that reflect device differences in BLE broadcast packets are extracted through traffic analysis.Finally,a MultiLayer Perceptron(MLP)model is employed to recognize the category of BLE devices.An experimental result on a dataset with 15 types of BLE devices shows that the identification accuracy of the proposed method can reach 99.8%,which accomplishes better performance over previous work.
基金National Natural Science Foundation of China(60532030)
文摘As an important scheme of future global mobile satellite communication systems to provide multimedia service, a Double-Layer Satellite Network （DLSN） with MEO satellites and LEO satellites is proposed. The Inter-Orbit-Links （IOLs） between layers is an essential factor, which affects the performances of the DLSN systems. Considering certain constellation parameters, the geometric characteristics of IOLs are described and the connectivity of MEO satellites and LEO satellites in the DLSN is analyzed. By computer simulation, the results show that IOLs should be selectively established according to certain parameters rather than the simple in-sight principle.
基金Supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Ministry of Education,Chinathe Natural Science Foundation of Tianjin City,China(No.06YFJMJC15000)
文摘Multilayer film was fabricated on an electrode surface by alternate layer-by-layer（LBL） adsorption of polycationic redox polymer（PEI-Fc） and dye-linked L-proline dehydrogenase（L-proDH）.The electrochemistry of the PEI-Fc/L-proDH multilayer modified electrode was investigated by cyclic voltammetry,and the enzyme catalysis mediated by the redox polymer was studied in a solution containing L-proline.It was observed that electron communication between L-proDH and the electrode was achieved with the help of PEI-Fc.A mathematical expression for the current response was evaluated based on the Michaelis-Menten kinetics mode,and the calculated currents fitted well with the experimental data.The kinetic analysis indicates that only a small fraction of the immobilized enzyme was efficiently electrically wired by the redox polymer.
