177,248 research outputs found
Secure GDoF of the Z-channel with Finite Precision CSIT: How Robust are Structured Codes?
Under the assumption of perfect channel state information at the transmitters
(CSIT), it is known that structured codes offer significant advantages for
secure communication in an interference network, e.g., structured jamming
signals based on lattice codes may allow a receiver to decode the sum of the
jamming signal and the signal being jammed, even though they cannot be
separately resolved due to secrecy constraints, subtract the aggregate jammed
signal, and then proceed to decode desired codewords at lower power levels. To
what extent are such benefits of structured codes fundamentally limited by
uncertainty in CSIT? To answer this question, we explore what is perhaps the
simplest setting where the question presents itself -- a Z interference channel
with secure communication. Using sum-set inequalities based on Aligned Images
bounds we prove that the GDoF benefits of structured codes are lost completely
under finite precision CSIT. The secure GDoF region of the Z interference
channel is obtained as a byproduct of the analysis.Comment: 34 pages, 10 figure
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
Secure Degrees of Freedom for Gaussian Channels with Interference: Structured Codes Outperform Gaussian Signaling
In this work, we prove that a positive secure degree of freedom is achievable
for a large class of Gaussian channels as long as the channel is not degraded
and the channel is fully connected. This class includes the MAC wire-tap
channel, the 2-user interference channel with confidential messages, the 2-user
interference channel with an external eavesdropper. Best known achievable
schemes to date for these channels use Gaussian signaling. In this work, we
show that structured codes outperform Gaussian random codes at high SNR when
channel gains are real numbers.Comment: 6 pages, Submitted to IEEE Globecom, March 200
Secure Satellite Communication Systems Design with Individual Secrecy Rate Constraints
In this paper, we study multibeam satellite secure communication through
physical (PHY) layer security techniques, i.e., joint power control and
beamforming. By first assuming that the Channel State Information (CSI) is
available and the beamforming weights are fixed, a novel secure satellite
system design is investigated to minimize the transmit power with individual
secrecy rate constraints. An iterative algorithm is proposed to obtain an
optimized power allocation strategy. Moreover, sub-optimal beamforming weights
are obtained by completely eliminating the co-channel interference and nulling
the eavesdroppers' signal simultaneously. In order to obtain jointly optimized
power allocation and beamforming strategy in some practical cases, e.g., with
certain estimation errors of the CSI, we further evaluate the impact of the
eavesdropper's CSI on the secure multibeam satellite system design. The
convergence of the iterative algorithm is proven under justifiable assumptions.
The performance is evaluated by taking into account the impact of the number of
antenna elements, number of beams, individual secrecy rate requirement, and
CSI. The proposed novel secure multibeam satellite system design can achieve
optimized power allocation to ensure the minimum individual secrecy rate
requirement. The results show that the joint beamforming scheme is more
favorable than fixed beamforming scheme, especially in the cases of a larger
number of satellite antenna elements and higher secrecy rate requirement.
Finally, we compare the results under the current satellite air-interface in
DVB-S2 and the results under Gaussian inputs.Comment: 34 pages, 10 figures, 1 table, submitted to "Transactions on
Information Forensics and Security
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