326 research outputs found
Secure Transmission for Relay Wiretap Channels in the Presence of Spatially Random Eavesdroppers
We propose a secure transmission scheme for a relay wiretap channel, where a
source communicates with a destination via a decode-and-forward relay in the
presence of spatially random-distributed eavesdroppers. We assume that the
source is equipped with multiple antennas, whereas the relay, the destination,
and the eavesdroppers are equipped with a single antenna each. In the proposed
scheme, in addition to information signals, the source transmits artificial
noise signals in order to confuse the eavesdroppers. With the target of
maximizing the secrecy throughput of the relay wiretap channel, we derive a
closed-form expression for the transmission outage probability and an
easy-to-compute expression for the secrecy outage probability. Using these
expressions, we determine the optimal power allocation factor and wiretap code
rates that guarantee the maximum secrecy throughput, while satisfying a secrecy
outage probability constraint. Furthermore, we examine the impact of source
antenna number on the secrecy throughput, showing that adding extra transmit
antennas at the source brings about a significant increase in the secrecy
throughput.Comment: 7 pages, 5 figures, accepted by IEEE Globecom 2015 Workshop on
Trusted Communications with Physical Layer Securit
Exploiting Full-duplex Receivers for Achieving Secret Communications in Multiuser MISO Networks
We consider a broadcast channel, in which a multi-antenna transmitter (Alice)
sends confidential information signals to legitimate users (Bobs) in
the presence of eavesdroppers (Eves). Alice uses MIMO precoding to generate
the information signals along with her own (Tx-based) friendly jamming.
Interference at each Bob is removed by MIMO zero-forcing. This, however, leaves
a "vulnerability region" around each Bob, which can be exploited by a nearby
Eve. We address this problem by augmenting Tx-based friendly jamming (TxFJ)
with Rx-based friendly jamming (RxFJ), generated by each Bob. Specifically,
each Bob uses self-interference suppression (SIS) to transmit a friendly
jamming signal while simultaneously receiving an information signal over the
same channel. We minimize the powers allocated to the information, TxFJ, and
RxFJ signals under given guarantees on the individual secrecy rate for each
Bob. The problem is solved for the cases when the eavesdropper's channel state
information is known/unknown. Simulations show the effectiveness of the
proposed solution. Furthermore, we discuss how to schedule transmissions when
the rate requirements need to be satisfied on average rather than
instantaneously. Under special cases, a scheduling algorithm that serves only
the strongest receivers is shown to outperform the one that schedules all
receivers.Comment: IEEE Transactions on Communication
Physical Layer Security in Wireless Ad Hoc Networks Under A Hybrid Full-/Half-Duplex Receiver Deployment Strategy
This paper studies physical layer security in a wireless ad hoc network with
numerous legitimate transmitter-receiver pairs and eavesdroppers. A hybrid
full-/half-duplex receiver deployment strategy is proposed to secure legitimate
transmissions, by letting a fraction of legitimate receivers work in the
full-duplex (FD) mode sending jamming signals to confuse eavesdroppers upon
their information receptions, and letting the other receivers work in the
half-duplex mode just receiving their desired signals. The objective of this
paper is to choose properly the fraction of FD receivers for achieving the
optimal network security performance. Both accurate expressions and tractable
approximations for the connection outage probability and the secrecy outage
probability of an arbitrary legitimate link are derived, based on which the
area secure link number, network-wide secrecy throughput and network-wide
secrecy energy efficiency are optimized respectively. Various insights into the
optimal fraction are further developed and its closed-form expressions are also
derived under perfect self-interference cancellation or in a dense network. It
is concluded that the fraction of FD receivers triggers a non-trivial trade-off
between reliability and secrecy, and the proposed strategy can significantly
enhance the network security performance.Comment: Journal paper, double-column 12 pages, 9 figures, accepted by IEEE
Transactions on Wireless Communications, 201
On the Throughput Cost of Physical Layer Security in Decentralized Wireless Networks
This paper studies the throughput of large-scale decentralized wireless
networks with physical layer security constraints. In particular, we are
interested in the question of how much throughput needs to be sacrificed for
achieving a certain level of security. We consider random networks where the
legitimate nodes and the eavesdroppers are distributed according to independent
two-dimensional Poisson point processes. The transmission capacity framework is
used to characterize the area spectral efficiency of secure transmissions with
constraints on both the quality of service (QoS) and the level of security.
This framework illustrates the dependence of the network throughput on key
system parameters, such as the densities of legitimate nodes and eavesdroppers,
as well as the QoS and security constraints. One important finding is that the
throughput cost of achieving a moderate level of security is quite low, while
throughput must be significantly sacrificed to realize a highly secure network.
We also study the use of a secrecy guard zone, which is shown to give a
significant improvement on the throughput of networks with high security
requirements.Comment: Accepted for publication in IEEE Transactions on Wireless
Communication
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
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