247 research outputs found
Adversarial Wiretap Channel with Public Discussion
Wyner's elegant model of wiretap channel exploits noise in the communication
channel to provide perfect secrecy against a computationally unlimited
eavesdropper without requiring a shared key. We consider an adversarial model
of wiretap channel proposed in [18,19] where the adversary is active: it
selects a fraction of the transmitted codeword to eavesdrop and a
fraction of the codeword to corrupt by "adding" adversarial error. It
was shown that this model also captures network adversaries in the setting of
1-round Secure Message Transmission [8]. It was proved that secure
communication (1-round) is possible if and only if .
In this paper we show that by allowing communicants to have access to a
public discussion channel (authentic communication without secrecy) secure
communication becomes possible even if . We formalize the
model of \awtppd protocol and for two efficiency measures, {\em information
rate } and {\em message round complexity} derive tight bounds. We also
construct a rate optimal protocol family with minimum number of message rounds.
We show application of these results to Secure Message Transmission with Public
Discussion (SMT-PD), and in particular show a new lower bound on transmission
rate of these protocols together with a new construction of an optimal SMT-PD
protocol
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
Information-theoretic Physical Layer Security for Satellite Channels
Shannon introduced the classic model of a cryptosystem in 1949, where Eve has
access to an identical copy of the cyphertext that Alice sends to Bob. Shannon
defined perfect secrecy to be the case when the mutual information between the
plaintext and the cyphertext is zero. Perfect secrecy is motivated by
error-free transmission and requires that Bob and Alice share a secret key.
Wyner in 1975 and later I.~Csisz\'ar and J.~K\"orner in 1978 modified the
Shannon model assuming that the channels are noisy and proved that secrecy can
be achieved without sharing a secret key. This model is called wiretap channel
model and secrecy capacity is known when Eve's channel is noisier than Bob's
channel.
In this paper we review the concept of wiretap coding from the satellite
channel viewpoint. We also review subsequently introduced stronger secrecy
levels which can be numerically quantified and are keyless unconditionally
secure under certain assumptions. We introduce the general construction of
wiretap coding and analyse its applicability for a typical satellite channel.
From our analysis we discuss the potential of keyless information theoretic
physical layer security for satellite channels based on wiretap coding. We also
identify system design implications for enabling simultaneous operation with
additional information theoretic security protocols
An Adversarial Learning Framework for Privacy Preserving Communications
We develop a machine learning-based approach that allows to achieve privacy in communications by exploiting an advantage at the physical layer. Our goal is to transmit useful data to the intended receiver while preventing sensitive data from leaking to an eavesdropper who has access to the channel. We adopt an adversarial approach involving two competing neural networks to learn efficient coding schemes that allow to regulate the tradeoff between quality and privacy.ope
Derandomizing Codes for the Binary Adversarial Wiretap Channel of Type II
We revisit the binary adversarial wiretap channel (AWTC) of type II in which
an active adversary can read a fraction and flip a fraction of codeword
bits. The semantic-secrecy capacity of the AWTC II is partially known, where
the best-known lower bound is non-constructive, proven via a random coding
argument that uses a large number (that is exponential in blocklength ) of
random bits to seed the random code. In this paper, we establish a new
derandomization result in which we match the best-known lower bound of
where is the binary entropy function via a random
code that uses a small seed of only bits. Our random code construction
is a novel application of pseudolinear codes -- a class of non-linear codes
that have -wise independent codewords when picked at random where is a
design parameter. As the key technical tool in our analysis, we provide a
soft-covering lemma in the flavor of Goldfeld, Cuff and Permuter (Trans. Inf.
Theory 2016) that holds for random codes with -wise independent codewords
Jamming Games in the MIMO Wiretap Channel With an Active Eavesdropper
This paper investigates reliable and covert transmission strategies in a
multiple-input multiple-output (MIMO) wiretap channel with a transmitter,
receiver and an adversarial wiretapper, each equipped with multiple antennas.
In a departure from existing work, the wiretapper possesses a novel capability
to act either as a passive eavesdropper or as an active jammer, under a
half-duplex constraint. The transmitter therefore faces a choice between
allocating all of its power for data, or broadcasting artificial interference
along with the information signal in an attempt to jam the eavesdropper
(assuming its instantaneous channel state is unknown). To examine the resulting
trade-offs for the legitimate transmitter and the adversary, we model their
interactions as a two-person zero-sum game with the ergodic MIMO secrecy rate
as the payoff function. We first examine conditions for the existence of
pure-strategy Nash equilibria (NE) and the structure of mixed-strategy NE for
the strategic form of the game.We then derive equilibrium strategies for the
extensive form of the game where players move sequentially under scenarios of
perfect and imperfect information. Finally, numerical simulations are presented
to examine the equilibrium outcomes of the various scenarios considered.Comment: 27 pages, 8 figures. To appear, IEEE Transactions on Signal
Processin
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