1,755 research outputs found
K-user Interference Channels: Achievable Secrecy Rate and Degrees of Freedom
In this work, we consider achievable secrecy rates for symmetric -user () interference channels with confidential messages. We find that nested
lattice codes and layered coding are useful in providing secrecy for these
channels. Achievable secrecy rates are derived for very strong interference. In
addition, we derive the secure degrees of freedom for a range of channel
parameters. As a by-product of our approach, we also demonstrate that nested
lattice codes are useful for K-user symmetric interference channels without
secrecy constraints in that they yield higher degrees of freedom than previous
results.Comment: 5 pages. To appear at IEEE ITW 2009, Volos, June 200
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
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
Weak Secrecy in the Multi-Way Untrusted Relay Channel with Compute-and-Forward
We investigate the problem of secure communications in a Gaussian multi-way
relay channel applying the compute-and-forward scheme using nested lattice
codes. All nodes employ half-duplex operation and can exchange confidential
messages only via an untrusted relay. The relay is assumed to be honest but
curious, i.e., an eavesdropper that conforms to the system rules and applies
the intended relaying scheme. We start with the general case of the
single-input multiple-output (SIMO) L-user multi-way relay channel and provide
an achievable secrecy rate region under a weak secrecy criterion. We show that
the securely achievable sum rate is equivalent to the difference between the
computation rate and the multiple access channel (MAC) capacity. Particularly,
we show that all nodes must encode their messages such that the common
computation rate tuple falls outside the MAC capacity region of the relay. We
provide results for the single-input single-output (SISO) and the
multiple-input single-input (MISO) L-user multi-way relay channel as well as
the two-way relay channel. We discuss these results and show the dependency
between channel realization and achievable secrecy rate. We further compare our
result to available results in the literature for different schemes and show
that the proposed scheme operates close to the compute-and-forward rate without
secrecy.Comment: submitted to JSAC Special Issue on Fundamental Approaches to Network
Coding in Wireless Communication System
Some results related to the conjecture by Belfiore and Sol\'e
In the first part of the paper, we consider the relation between kissing
number and the secrecy gain. We show that on an -dimensional even
unimodular lattice, if the shortest vector length is , then as the
number of vectors of length decreases, the secrecy gain increases. We will
also prove a similar result on general unimodular lattices. We will also
consider the situations with shorter vectors. Furthermore, assuming the
conjecture by Belfiore and Sol\'e, we will calculate the difference between
inverses of secrecy gains as the number of vectors varies. We will show by an
example that there exist two lattices in the same dimension with the same
shortest vector length and the same kissing number, but different secrecy
gains. Finally, we consider some cases of a question by Elkies by providing an
answer for a special class of lattices assuming the conjecture of Belfiore and
Sol\'e. We will also get a conditional improvement on some Gaulter's results
concerning the conjecture.Comment: This paper contains the note http://arxiv.org/abs/1209.3573. However,
there are several new results, including the results concerning a conjecture
by Elkie
Secure Compute-and-Forward in a Bidirectional Relay
We consider the basic bidirectional relaying problem, in which two users in a
wireless network wish to exchange messages through an intermediate relay node.
In the compute-and-forward strategy, the relay computes a function of the two
messages using the naturally-occurring sum of symbols simultaneously
transmitted by user nodes in a Gaussian multiple access (MAC) channel, and the
computed function value is forwarded to the user nodes in an ensuing broadcast
phase. In this paper, we study the problem under an additional security
constraint, which requires that each user's message be kept secure from the
relay. We consider two types of security constraints: perfect secrecy, in which
the MAC channel output seen by the relay is independent of each user's message;
and strong secrecy, which is a form of asymptotic independence. We propose a
coding scheme based on nested lattices, the main feature of which is that given
a pair of nested lattices that satisfy certain "goodness" properties, we can
explicitly specify probability distributions for randomization at the encoders
to achieve the desired security criteria. In particular, our coding scheme
guarantees perfect or strong secrecy even in the absence of channel noise. The
noise in the channel only affects reliability of computation at the relay, and
for Gaussian noise, we derive achievable rates for reliable and secure
computation. We also present an application of our methods to the multi-hop
line network in which a source needs to transmit messages to a destination
through a series of intermediate relays.Comment: v1 is a much expanded and updated version of arXiv:1204.6350; v2 is a
minor revision to fix some notational issues; v3 is a much expanded and
updated version of v2, and contains results on both perfect secrecy and
strong secrecy; v3 is a revised manuscript submitted to the IEEE Transactions
on Information Theory in April 201
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