4,260 research outputs found
Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey
This paper provides a comprehensive review of the domain of physical layer
security in multiuser wireless networks. The essential premise of
physical-layer security is to enable the exchange of confidential messages over
a wireless medium in the presence of unauthorized eavesdroppers without relying
on higher-layer encryption. This can be achieved primarily in two ways: without
the need for a secret key by intelligently designing transmit coding
strategies, or by exploiting the wireless communication medium to develop
secret keys over public channels. The survey begins with an overview of the
foundations dating back to the pioneering work of Shannon and Wyner on
information-theoretic security. We then describe the evolution of secure
transmission strategies from point-to-point channels to multiple-antenna
systems, followed by generalizations to multiuser broadcast, multiple-access,
interference, and relay networks. Secret-key generation and establishment
protocols based on physical layer mechanisms are subsequently covered.
Approaches for secrecy based on channel coding design are then examined, along
with a description of inter-disciplinary approaches based on game theory and
stochastic geometry. The associated problem of physical-layer message
authentication is also introduced briefly. The survey concludes with
observations on potential research directions in this area.Comment: 23 pages, 10 figures, 303 refs. arXiv admin note: text overlap with
arXiv:1303.1609 by other authors. IEEE Communications Surveys and Tutorials,
201
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
Relay Selection for Wireless Communications Against Eavesdropping: A Security-Reliability Tradeoff Perspective
This article examines the secrecy coding aided wireless communications from a
source to a destination in the presence of an eavesdropper from a
security-reliability tradeoff (SRT) perspective. Explicitly, the security is
quantified in terms of the intercept probability experienced at the
eavesdropper, while the outage probability encountered at the destination is
used to measure the transmission reliability. We characterize the SRT of
conventional direct transmission from the source to the destination and show
that if the outage probability is increased, the intercept probability
decreases, and vice versa. We first demonstrate that the employment of relay
nodes for assisting the source-destination transmissions is capable of
defending against eavesdropping, followed by quantifying the benefits of
single-relay selection (SRS) as well as of multi-relay selection (MRS) schemes.
More specifically, in the SRS scheme, only the single "best" relay is selected
for forwarding the source signal to the destination, whereas the MRS scheme
allows multiple relays to participate in this process. It is illustrated that
both the SRS and MRS schemes achieve a better SRT than the conventional direct
transmission, especially upon increasing the number of relays. Numerical
results also show that as expected, the MRS outperforms the SRS in terms of its
SRT. Additionally, we present some open challenges and future directions for
the wireless relay aided physical-layer security.Comment: 16 pages, IEEE Network, 201
Secrecy Outage and Diversity Analysis of Cognitive Radio Systems
In this paper, we investigate the physical-layer security of a multi-user
multi-eavesdropper cognitive radio system, which is composed of multiple
cognitive users (CUs) transmitting to a common cognitive base station (CBS),
while multiple eavesdroppers may collaborate with each other or perform
independently in intercepting the CUs-CBS transmissions, which are called the
coordinated and uncoordinated eavesdroppers, respectively. Considering multiple
CUs available, we propose the round-robin scheduling as well as the optimal and
suboptimal user scheduling schemes for improving the security of CUs-CBS
transmissions against eavesdropping attacks. Specifically, the optimal user
scheduling is designed by assuming that the channel state information (CSI) of
all links from CUs to CBS, to primary user (PU) and to eavesdroppers are
available. By contrast, the suboptimal user scheduling only requires the CSI of
CUs-CBS links without the PU's and eavesdroppers' CSI. We derive closed-form
expressions of the secrecy outage probability of these three scheduling schemes
in the presence of the coordinated and uncoordinated eavesdroppers. We also
carry out the secrecy diversity analysis and show that the round-robin
scheduling achieves the diversity order of only one, whereas the optimal and
suboptimal scheduling schemes obtain the full secrecy diversity, no matter
whether the eavesdroppers collaborate or not. In addition, numerical secrecy
outage results demonstrate that for both the coordinated and uncoordinated
eavesdroppers, the optimal user scheduling achieves the best security
performance and the round-robin scheduling performs the worst. Finally, upon
increasing the number of CUs, the secrecy outage probabilities of the optimal
and suboptimal user scheduling schemes both improve significantly.Comment: 16 pages, 5 figures, accepted to appear, IEEE Journal on Selected
Areas in Communications, 201
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