19 research outputs found
A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends
This paper examines the security vulnerabilities and threats imposed by the
inherent open nature of wireless communications and to devise efficient defense
mechanisms for improving the wireless network security. We first summarize the
security requirements of wireless networks, including their authenticity,
confidentiality, integrity and availability issues. Next, a comprehensive
overview of security attacks encountered in wireless networks is presented in
view of the network protocol architecture, where the potential security threats
are discussed at each protocol layer. We also provide a survey of the existing
security protocols and algorithms that are adopted in the existing wireless
network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term
evolution (LTE) systems. Then, we discuss the state-of-the-art in
physical-layer security, which is an emerging technique of securing the open
communications environment against eavesdropping attacks at the physical layer.
We also introduce the family of various jamming attacks and their
counter-measures, including the constant jammer, intermittent jammer, reactive
jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the
integration of physical-layer security into existing authentication and
cryptography mechanisms for further securing wireless networks. Finally, some
technical challenges which remain unresolved at the time of writing are
summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201
Disco Intelligent Reflecting Surfaces: Active Channel Aging for Fully-Passive Jamming Attacks
Due to the open communications environment in wireless channels, wireless
networks are vulnerable to jamming attacks. However, existing approaches for
jamming rely on knowledge of the legitimate users' (LUs') channels, extra
jamming power, or both. To raise concerns about the potential threats posed by
illegitimate intelligent reflecting surfaces (IRSs), we propose an alternative
method to launch jamming attacks on LUs without either LU channel state
information (CSI) or jamming power. The proposed approach employs an
adversarial IRS with random phase shifts, referred to as a "disco" IRS (DIRS),
that acts like a "disco ball" to actively age the LUs' channels. Such active
channel aging (ACA) interference can be used to launch jamming attacks on
multi-user multiple-input single-output (MU-MISO) systems. The proposed
DIRS-based fully-passive jammer (FPJ) can jam LUs with no additional jamming
power or knowledge of the LU CSI, and it can not be mitigated by classical
anti-jamming approaches. A theoretical analysis of the proposed DIRS-based FPJ
that provides an evaluation of the DIRS-based jamming attacks is derived. Based
on this detailed theoretical analysis, some unique properties of the proposed
DIRS-based FPJ can be obtained. Furthermore, a design example of the proposed
DIRS-based FPJ based on one-bit quantization of the IRS phases is demonstrated
to be sufficient for implementing the jamming attack. In addition, numerical
results are provided to show the effectiveness of the derived theoretical
analysis and the jamming impact of the proposed DIRS-based FPJ
A novel MAC Protocol for Cognitive Radio Networks
In Partial Fulfilment of the Requirements for the Degree Doctor of Philosophy from the University of BedfordshireThe scarcity of bandwidth in the radio spectrum has become more vital since the demand for wireless applications has increased. Most of the spectrum bands have been allocated although many studies have shown that these bands are significantly underutilized most of the time. The problem of unavailability of spectrum bands and the inefficiency in their utilization have been smartly addressed by the cognitive radio (CR) technology which is an opportunistic network that senses the environment, observes the network changes, and then uses knowledge gained from the prior interaction with the network to make intelligent decisions by dynamically adapting transmission characteristics. In this thesis, recent research and survey about the advances in theory and applications of cognitive radio technology has been reviewed. The thesis starts with the essential background on cognitive radio techniques and systems and discusses those characteristics of CR technology, such as standards, applications and challenges that all can help make software radio more personal. It then presents advanced level material by extensively reviewing the work done so far in the area of cognitive radio networks and more specifically in medium access control (MAC) protocol of CR. The list of references will be useful to both researchers and practitioners in this area. Also, it can be adopted as a graduate-level textbook for an advanced course on wireless communication networks.
The development of new technologies such as Wi-Fi, cellular phones, Bluetooth, TV broadcasts and satellite has created immense demand for radio spectrum which is a limited natural resource ranging from 30KHz to 300GHz. For every wireless application, some portion of the radio spectrum needs to be purchased, and the Federal Communication Commission (FCC) allocates the spectrum for some fee for such services. This static allocation of the radio spectrum has led to various problems such as saturation in some bands, scarcity, and lack of radio resources to new wireless applications. Most of the frequencies in the radio spectrum have been allocated although many studies have shown that the allocated bands are not being used efficiently. The CR technology is one of the effective solutions to the shortage of spectrum and the inefficiency of its utilization. In this thesis, a detailed investigation on issues related to the protocol design for cognitive radio networks with particular emphasis on the MAC layer is presented. A novel Dynamic and Decentralized and Hybrid MAC (DDH-MAC) protocol that lies between the CR MAC protocol families of globally available common control channel (GCCC) and local control channel (non-GCCC). First, a multi-access channel MAC protocol, which integrates the best features of both GCCC and non-GCCC, is proposed. Second, an enhancement to the protocol is proposed by enabling it to access more than one control channel at the same time. The cognitive users/secondary users (SUs) always have access to one control channel and they can identify and exploit the vacant channels by dynamically switching across the different control channels. Third, rapid and efficient exchange of CR control information has been proposed to reduce delays due to the opportunistic nature of CR. We have calculated the pre-transmission time for CR and investigate how this time can have a significant effect on nodes holding a delay sensitive data. Fourth, an analytical model, including a Markov chain model, has been proposed. This analytical model will rigorously analyse the performance of our proposed DDH-MAC protocol in terms of aggregate throughput, access delay, and spectrum opportunities in both the saturated and non-saturated networks. Fifth, we develop a simulation model for the DDH-MAC protocol using OPNET Modeler and investigate its performance for queuing delays, bit error rates, backoff slots and throughput. It could be observed from both the numerical and simulation results that when compared with existing CR MAC protocols our proposed MAC protocol can significantly improve the spectrum utilization efficiency of wireless networks. Finally, we optimize the performance of our proposed MAC protocol by incorporating multi-level security and making it energy efficient
Secure Data Collection and Analysis in Smart Health Monitoring
Smart health monitoring uses real-time monitored data to support diagnosis, treatment, and health decision-making in modern smart healthcare systems and benefit our daily life. The accurate health monitoring and prompt transmission of health data are facilitated by the ever-evolving on-body sensors, wireless communication technologies, and wireless sensing techniques. Although the users have witnessed the convenience of smart health monitoring, severe privacy and security concerns on the valuable and sensitive collected data come along with the merit. The data collection, transmission, and analysis are vulnerable to various attacks, e.g., eavesdropping, due to the open nature of wireless media, the resource constraints of sensing devices, and the lack of security protocols. These deficiencies not only make conventional cryptographic methods not applicable in smart health monitoring but also put many obstacles in the path of designing privacy protection mechanisms.
In this dissertation, we design dedicated schemes to achieve secure data collection and analysis in smart health monitoring. The first two works propose two robust and secure authentication schemes based on Electrocardiogram (ECG), which outperform traditional user identity authentication schemes in health monitoring, to restrict the access to collected data to legitimate users. To improve the practicality of ECG-based authentication, we address the nonuniformity and sensitivity of ECG signals, as well as the noise contamination issue. The next work investigates an extended authentication goal, denoted as wearable-user pair authentication. It simultaneously authenticates the user identity and device identity to provide further protection. We exploit the uniqueness of the interference between different wireless protocols, which is common in health monitoring due to devices\u27 varying sensing and transmission demands, and design a wearable-user pair authentication scheme based on the interference. However, the harm of this interference is also outstanding. Thus, in the fourth work, we use wireless human activity recognition in health monitoring as an example and analyze how this interference may jeopardize it. We identify a new attack that can produce false recognition result and discuss potential countermeasures against this attack. In the end, we move to a broader scenario and protect the statistics of distributed data reported in mobile crowd sensing, a common practice used in public health monitoring for data collection. We deploy differential privacy to enable the indistinguishability of workers\u27 locations and sensing data without the help of a trusted entity while meeting the accuracy demands of crowd sensing tasks
Secure Routing and Medium Access Protocols inWireless Multi-hop Networks
While the rapid proliferation of mobile devices along with the tremendous growth of various applications using
wireless multi-hop networks have significantly facilitate our human life, securing and ensuring high quality
services of these networks are still a primary concern. In particular, anomalous protocol operation in wireless
multi-hop networks has recently received considerable attention in the research community. These relevant security
issues are fundamentally different from those of wireline networks due to the special characteristics of
wireless multi-hop networks, such as the limited energy resources and the lack of centralized control. These issues
are extremely hard to cope with due to the absence of trust relationships between the nodes.
To enhance security in wireless multi-hop networks, this dissertation addresses both MAC and routing layers
misbehaviors issues, with main focuses on thwarting black hole attack in proactive routing protocols like OLSR,
and greedy behavior in IEEE 802.11 MAC protocol. Our contributions are briefly summarized as follows.
As for black hole attack, we analyze two types of attack scenarios: one is launched at routing layer, and the
other is cross layer. We then provide comprehensive analysis on the consequences of this attack and propose
effective countermeasures.
As for MAC layer misbehavior, we particularly study the adaptive greedy behavior in the context of Wireless
Mesh Networks (WMNs) and propose FLSAC (Fuzzy Logic based scheme to Struggle against Adaptive Cheaters)
to cope with it. A new characterization of the greedy behavior in Mobile Ad Hoc Networks (MANETs) is also
introduced. Finally, we design a new backoff scheme to quickly detect the greedy nodes that do not comply with
IEEE 802.11 MAC protocol, together with a reaction scheme that encourages the greedy nodes to become honest
rather than punishing them
Secure Routing and Medium Access Protocols inWireless Multi-hop Networks
While the rapid proliferation of mobile devices along with the tremendous growth of various applications using
wireless multi-hop networks have significantly facilitate our human life, securing and ensuring high quality
services of these networks are still a primary concern. In particular, anomalous protocol operation in wireless
multi-hop networks has recently received considerable attention in the research community. These relevant security
issues are fundamentally different from those of wireline networks due to the special characteristics of
wireless multi-hop networks, such as the limited energy resources and the lack of centralized control. These issues
are extremely hard to cope with due to the absence of trust relationships between the nodes.
To enhance security in wireless multi-hop networks, this dissertation addresses both MAC and routing layers
misbehaviors issues, with main focuses on thwarting black hole attack in proactive routing protocols like OLSR,
and greedy behavior in IEEE 802.11 MAC protocol. Our contributions are briefly summarized as follows.
As for black hole attack, we analyze two types of attack scenarios: one is launched at routing layer, and the
other is cross layer. We then provide comprehensive analysis on the consequences of this attack and propose
effective countermeasures.
As for MAC layer misbehavior, we particularly study the adaptive greedy behavior in the context of Wireless
Mesh Networks (WMNs) and propose FLSAC (Fuzzy Logic based scheme to Struggle against Adaptive Cheaters)
to cope with it. A new characterization of the greedy behavior in Mobile Ad Hoc Networks (MANETs) is also
introduced. Finally, we design a new backoff scheme to quickly detect the greedy nodes that do not comply with
IEEE 802.11 MAC protocol, together with a reaction scheme that encourages the greedy nodes to become honest
rather than punishing them
Security in Distributed, Grid, Mobile, and Pervasive Computing
This book addresses the increasing demand to guarantee privacy, integrity, and availability of resources in networks and distributed systems. It first reviews security issues and challenges in content distribution networks, describes key agreement protocols based on the Diffie-Hellman key exchange and key management protocols for complex distributed systems like the Internet, and discusses securing design patterns for distributed systems. The next section focuses on security in mobile computing and wireless networks. After a section on grid computing security, the book presents an overview of security solutions for pervasive healthcare systems and surveys wireless sensor network security