Qingxu Xiong

Bio: Qingxu Xiong is an academic researcher from Beihang University. The author has contributed to research in topics: Microstrip & Authentication. The author has an hindex of 6, co-authored 6 publications receiving 306 citations.

Role-Dependent Privacy Preservation for Secure V2G Networks in the Smart Grid

Abstract: Vehicle-to-grid (V2G), involving both charging and discharging of battery vehicles (BVs), enhances the smart grid substantially to alleviate peaks in power consumption. In a V2G scenario, the communications between BVs and power grid may confront severe cyber security vulnerabilities. Traditionally, authentication mechanisms are solely designed for the BVs when they charge electricity as energy customers. In this paper, we first show that, when a BV interacts with the power grid, it may act in one of three roles: 1) energy demand (i.e., a customer); 2) energy storage; and 3) energy supply (i.e., a generator). In each role, we further demonstrate that the BV has dissimilar security and privacy concerns. Hence, the traditional approach that only considers BVs as energy customers is not universally applicable for the interactions in the smart grid. To address this new security challenge, we propose a role-dependent privacy preservation scheme (ROPS) to achieve secure interactions between a BV and power grid. In the ROPS, a set of interlinked subprotocols is proposed to incorporate different privacy considerations when a BV acts as a customer, storage, or a generator. We also outline both centralized and distributed discharging operations when a BV feeds energy back into the grid. Finally, security analysis is performed to indicate that the proposed ROPS owns required security and privacy properties and can be a highly potential security solution for V2G networks in the smart grid. The identified security challenge as well as the proposed ROPS scheme indicates that role-awareness is crucial for secure V2G networks.

Shared Authority Based Privacy-Preserving Authentication Protocol in Cloud Computing

Abstract: Cloud computing is an emerging data interactive paradigm to realize users' data remotely stored in an online cloud server. Cloud services provide great conveniences for the users to enjoy the on-demand cloud applications without considering the local infrastructure limitations. During the data accessing, different users may be in a collaborative relationship, and thus data sharing becomes significant to achieve productive benefits. The existing security solutions mainly focus on the authentication to realize that a user's privative data cannot be illegally accessed, but neglect a subtle privacy issue during a user challenging the cloud server to request other users for data sharing. The challenged access request itself may reveal the user's privacy no matter whether or not it can obtain the data access permissions. In this paper, we propose a shared authority based privacy-preserving authentication protocol (SAPA) to address above privacy issue for cloud storage. In the SAPA, 1) shared access authority is achieved by anonymous access request matching mechanism with security and privacy considerations (e.g., authentication, data anonymity, user privacy, and forward security); 2) attribute based access control is adopted to realize that the user can only access its own data fields; 3) proxy re-encryption is applied to provide data sharing among the multiple users. Meanwhile, universal composability (UC) model is established to prove that the SAPA theoretically has the design correctness. It indicates that the proposed protocol is attractive for multi-user collaborative cloud applications.

Grouping-Proofs-Based Authentication Protocol for Distributed RFID Systems

Abstract: Along with radio frequency identification (RFID) becoming ubiquitous, security issues have attracted extensive attentions. Most studies focus on the single-reader and single-tag case to provide security protection, which leads to certain limitations for diverse applications. This paper proposes a grouping-proofs-based authentication protocol (GUPA) to address the security issue for multiple readers and tags simultaneous identification in distributed RFID systems. In GUPA, distributed authentication mode with independent subgrouping proofs is adopted to enhance hierarchical protection; an asymmetric denial scheme is applied to grant fault-tolerance capabilities against an illegal reader or tag; and a sequence-based odd-even alternation group subscript is presented to define a function for secret updating. Meanwhile, GUPA is analyzed to be robust enough to resist major attacks such as replay, forgery, tracking, and denial of proof. Furthermore, performance analysis shows that compared with the known grouping-proof or yoking-proof-based protocols, GUPA has lower communication overhead and computation load. It indicates that GUPA realizing both secure and simultaneous identification is efficient for resource-constrained distributed RFID systems.

Design of Planar Dual and Triple Narrow-Band Bandstop Filters with Independently Controlled Stopbands and Improved Spurious Response

Abstract: A novel design of planar dual and triple narrow-band bandstop fllter is presented by adopting the proposed meandered slot defected microstrip structure (MS-DMS) and the simplifled spiral microstrip resonator (SSMR). Through this design, the stopbands of the dual- and triple-band bandstop fllters can be individually controlled and the improved spurious responses are achieved. First, the fundamental and the flrst spurious resonances of the MS-DMS and SSMR are analyzed to provide the design rules. Then, by utilizing the prominent stopband of the MS-DMS and the stopband produced by the SSMR coupled to main microstrip line, a dual narrow- band bandstop fllter is constructed before its design procedure is outlined. Based on above investigations, a triple narrow-band bandstop fllter is implemented by inserting extra SSMRs to another side of the main microstrip line of the dual-band fllter to generate a new stopband. To verify the aforementioned design concepts, a dual and triple narrow-band bandstop fllter are designed, simulated and tested. Both the simulation and measurement indicate that the fabricated fllters exhibit good stopband/passband performance and improved flrst spurious resonance. Moreover, these fllters are simple to design and quite compatible with planar fabrication technique, making them very attractive for practical applications.

A Novel Miniaturized Dual-Band Bandstop Filter Using Dual-Plane Defected Structures

Abstract: A novel miniaturized dual-band bandstop fllter (DBBSF) is proposed by using the T-shaped defected microstrip structures (DMSs) and the U-shaped defected ground structures (DGSs) in this paper. The layout of the dual-band bandstop resonator (DBBSR) is presented at flrst. The dual stopbands of the DBBSR can be separately controlled since the mutual coupling of the defected structures is negligible. The working principles of the T-shaped DMS and U-shaped DGS are then provided and their design process is summarized. On the basis of the DBBSR, the design methodology of the compact DBBSF is proposed before its design procedures are presented. Following the design procedures, a second-order and third- order DBBSFs with Butterworth frequency response are designed, simulated and fabricated. The equivalent circuit models of the designed fllters are also developed. Full-wave simulation results of the fabricated DBBSFs are in good agreement with the circuit simulation and measurement results, validating our proposed design methodology.

Data Security and Privacy-Preserving in Edge Computing Paradigm: Survey and Open Issues

Abstract: With the explosive growth of Internet of Things devices and massive data produced at the edge of the network, the traditional centralized cloud computing model has come to a bottleneck due to the bandwidth limitation and resources constraint. Therefore, edge computing, which enables storing and processing data at the edge of the network, has emerged as a promising technology in recent years. However, the unique features of edge computing, such as content perception, real-time computing, and parallel processing, has also introduced several new challenges in the field of data security and privacy-preserving, which are also the key concerns of the other prevailing computing paradigms, such as cloud computing, mobile cloud computing, and fog computing. Despites its importance, there still lacks a survey on the recent research advance of data security and privacy-preserving in the field of edge computing. In this paper, we present a comprehensive analysis of the data security and privacy threats, protection technologies, and countermeasures inherent in edge computing. Specifically, we first make an overview of edge computing, including forming factors, definition, architecture, and several essential applications. Next, a detailed analysis of data security and privacy requirements, challenges, and mechanisms in edge computing are presented. Then, the cryptography-based technologies for solving data security and privacy issues are summarized. The state-of-the-art data security and privacy solutions in edge-related paradigms are also surveyed. Finally, we propose several open research directions of data security in the field of edge computing.

Spoofing-Jamming Attack Strategy Using Optimal Power Distributions in Wireless Smart Grid Networks

Abstract: As an emerging fast-growing technology, smart grid networks (SGNs) have been dramatically accepted by the current power supply industry for achieving high performance power governance system. The wireless SGN (WSGNs) have enabled numerous flexible power management solutions without the restrictions of the wired infrastructure. The cognitive radio network (CRN) is one of the widely deployed wireless networking approaches. The communication security is a major concern while CRN is used in WSGNs. Currently, jamming and spoofing are two common attack approaches that are active in the deployment of WSGNs when using CRNs. This paper proposes an attack strategy, maximum attacking strategy using spoofing and jamming (MASS-SJ), which utilizes an optimal power distribution to maximize the adversarial effects. Spoofing and jamming attacks are launched in a dynamic manner in order to interfere with the maximum number of signal channels. Our proposed approach has been evaluated by our experiments and the results have shown the positive performance of using MAS-SJ.

CCPA: Coordinated Cyber-Physical Attacks and Countermeasures in Smart Grid

Abstract: Smart grid, as one of the most critical infrastructures, is vulnerable to a wide variety of cyber and/or physical attacks. Recently, a new category of threats to smart grid, named coordinated cyber-physical attacks (CCPAs), are emerging. A key feature of CCPAs is to leverage cyber attacks to mask physical attacks which can cause power outages and potentially trigger cascading failures. In this paper, we investigate CCPAs in smart grid and show that an adversary can carefully synthesize a false data injection attack vector based on phasor measurement unit (PMU) measurements to neutralize the impact of physical attack vector, such that CCPAs could circumvent bad data detection without being detected. Specifically, we present two potential CCPAs, namely replay and optimized CCPAs, respectively, and analyze the adversary’s required capability to construct them. Based on the analytical results, countermeasures are proposed to detect the two kinds of CCPAs, through known-secure PMU measurement verification (in the cyber space) and online tracking of the power system equivalent impedance (in the physical space), respectively. The implementation of CCPAs in smart grid and the effectiveness of countermeasures are demonstrated by using an illustrative 4-bus power system and the IEEE 9-bus, 14-bus, 30-bus, 118-bus, and 300-bus test power systems.

Balancing Power Demand Through EV Mobility in Vehicle-to-Grid Mobile Energy Networks

Abstract: Vehicle-to-grid (V2G) technology enables bidirectional energy flow between electric vehicles (EVs) and power grid, which provides flexible demand response management (DRM) for the reliability of smart grid. EV mobility is a unique and inherent feature of the V2G system. However, the inter-relationship between EV mobility and DRM is not obvious. In this paper, we focus on the exploration of EV mobility to impact DRM in V2G systems in smart grid. We first present a dynamic complex network model of V2G mobile energy networks, considering the fact that EVs travel across multiple districts, and hence EVs can be acting as energy transporters among different districts. We formulate the districts’ DRM dynamics, which is coupled with each other through EV fleets. In addition, a complex network synchronization method is proposed to analyze the dynamic behavior in V2G mobile energy networks. Numerical results show that EVs mobility of symmetrical EV fleet is able to achieve synchronous stability of network and balance the power demand among different districts. This observation is also validated by simulation with real world data.