647 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
To Obtain or not to Obtain CSI in the Presence of Hybrid Adversary
We consider the wiretap channel model under the presence of a hybrid, half
duplex adversary that is capable of either jamming or eavesdropping at a given
time. We analyzed the achievable rates under a variety of scenarios involving
different methods for obtaining transmitter CSI. Each method provides a
different grade of information, not only to the transmitter on the main
channel, but also to the adversary on all channels. Our analysis shows that
main CSI is more valuable for the adversary than the jamming CSI in both
delay-limited and ergodic scenarios. Similarly, in certain cases under the
ergodic scenario, interestingly, no CSI may lead to higher achievable secrecy
rates than with CSI.Comment: 8 pages, 3 figure
Opportunistic Secrecy with a Strict Delay Constraint
We investigate the delay limited secrecy capacity of the flat fading channel
under two different assumptions on the available transmitter channel state
information (CSI). The first scenario assumes perfect prior knowledge of both
the main and eavesdropper channel gains. Here, upper and lower bounds on the
delay limited secrecy capacity are derived, and shown to be tight in the high
signal-to-noise ratio (SNR) regime. In the second scenario, only the main
channel CSI is assumed to be available at the transmitter where, remarkably, we
establish the achievability of a non-zero delay-limited secure rate, for a wide
class of channel distributions, with a high probability. In the two cases, our
achievability arguments are based on a novel two-stage key-sharing approach
that overcomes the secrecy outage phenomenon observed in earlier works.Comment: Submitted to IEEE Transactions on Information Theor
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