31,828 research outputs found
On Secure Network Coding with Nonuniform or Restricted Wiretap Sets
The secrecy capacity of a network, for a given collection of permissible
wiretap sets, is the maximum rate of communication such that observing links in
any permissible wiretap set reveals no information about the message. This
paper considers secure network coding with nonuniform or restricted wiretap
sets, for example, networks with unequal link capacities where a wiretapper can
wiretap any subset of links, or networks where only a subset of links can
be wiretapped. Existing results show that for the case of uniform wiretap sets
(networks with equal capacity links/packets where any can be wiretapped),
the secrecy capacity is given by the cut-set bound, and can be achieved by
injecting random keys at the source which are decoded at the sink along
with the message. This is the case whether or not the communicating users have
information about the choice of wiretap set. In contrast, we show that for the
nonuniform case, the cut-set bound is not achievable in general when the
wiretap set is unknown, whereas it is achievable when the wiretap set is made
known. We give achievable strategies where random keys are canceled at
intermediate non-sink nodes, or injected at intermediate non-source nodes.
Finally, we show that determining the secrecy capacity is a NP-hard problem.Comment: 24 pages, revision submitted to IEEE Transactions on Information
Theor
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
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
Routing for Security in Networks with Adversarial Nodes
We consider the problem of secure unicast transmission between two nodes in a
directed graph, where an adversary eavesdrops/jams a subset of nodes. This
adversarial setting is in contrast to traditional ones where the adversary
controls a subset of links. In particular, we study, in the main, the class of
routing-only schemes (as opposed to those allowing coding inside the network).
Routing-only schemes usually have low implementation complexity, yet a
characterization of the rates achievable by such schemes was open prior to this
work. We first propose an LP based solution for secure communication against
eavesdropping, and show that it is information-theoretically rate-optimal among
all routing-only schemes. The idea behind our design is to balance information
flow in the network so that no subset of nodes observe "too much" information.
Interestingly, we show that the rates achieved by our routing-only scheme are
always at least as good as, and sometimes better, than those achieved by
"na\"ive" network coding schemes (i.e. the rate-optimal scheme designed for the
traditional scenario where the adversary controls links in a network rather
than nodes.) We also demonstrate non-trivial network coding schemes that
achieve rates at least as high as (and again sometimes better than) those
achieved by our routing schemes, but leave open the question of characterizing
the optimal rate-region of the problem under all possible coding schemes. We
then extend these routing-only schemes to the adversarial node-jamming
scenarios and show similar results. During the journey of our investigation, we
also develop a new technique that has the potential to derive non-trivial
bounds for general secure-communication schemes
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