5,254 research outputs found
Quantum Security for the Physical Layer
The physical layer describes how communication signals are encoded and
transmitted across a channel. Physical security often requires either
restricting access to the channel or performing periodic manual inspections. In
this tutorial, we describe how the field of quantum communication offers new
techniques for securing the physical layer. We describe the use of quantum
seals as a unique way to test the integrity and authenticity of a communication
channel and to provide security for the physical layer. We present the
theoretical and physical underpinnings of quantum seals including the quantum
optical encoding used at the transmitter and the test for non-locality used at
the receiver. We describe how the envisioned quantum physical sublayer senses
tampering and how coordination with higher protocol layers allow quantum seals
to influence secure routing or tailor data management methods. We conclude by
discussing challenges in the development of quantum seals, the overlap with
existing quantum key distribution cryptographic services, and the relevance of
a quantum physical sublayer to the future of communication security.Comment: 7 pages, 6 figure
Field Test of Classical Symmetric Encryption with Continuous Variable Quantum Key Distribution
We report on the design and performance of a point-to-point classical
symmetric encryption link with fast key renewal provided by a Continuous
Variable Quantum Key Distribution (CVQKD) system. Our system was operational
and able to encrypt point-to-point communications during more than six months,
from the end of July 2010 until the beginning of February 2011. This field test
was the first demonstration of the reliability of a CVQKD system over a long
period of time in a server room environment. This strengthens the potential of
CVQKD for information technology security infrastructure deployments
Two-Layered Superposition of Broadcast/Multicast and Unicast Signals in Multiuser OFDMA Systems
We study optimal delivery strategies of one common and independent
messages from a source to multiple users in wireless environments. In
particular, two-layered superposition of broadcast/multicast and unicast
signals is considered in a downlink multiuser OFDMA system. In the literature
and industry, the two-layer superposition is often considered as a pragmatic
approach to make a compromise between the simple but suboptimal orthogonal
multiplexing (OM) and the optimal but complex fully-layered non-orthogonal
multiplexing. In this work, we show that only two-layers are necessary to
achieve the maximum sum-rate when the common message has higher priority than
the individual unicast messages, and OM cannot be sum-rate optimal in
general. We develop an algorithm that finds the optimal power allocation over
the two-layers and across the OFDMA radio resources in static channels and a
class of fading channels. Two main use-cases are considered: i) Multicast and
unicast multiplexing when users with uplink capabilities request both
common and independent messages, and ii) broadcast and unicast multiplexing
when the common message targets receive-only devices and users with uplink
capabilities additionally request independent messages. Finally, we develop a
transceiver design for broadcast/multicast and unicast superposition
transmission based on LTE-A-Pro physical layer and show with numerical
evaluations in mobile environments with multipath propagation that the capacity
improvements can be translated into significant practical performance gains
compared to the orthogonal schemes in the 3GPP specifications. We also analyze
the impact of real channel estimation and show that significant gains in terms
of spectral efficiency or coverage area are still available even with
estimation errors and imperfect interference cancellation for the two-layered
superposition system
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
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