26,696 research outputs found
Secure Partial Repair in Wireless Caching Networks with Broadcast Channels
We study security in partial repair in wireless caching networks where parts
of the stored packets in the caching nodes are susceptible to be erased. Let us
denote a caching node that has lost parts of its stored packets as a sick
caching node and a caching node that has not lost any packet as a healthy
caching node. In partial repair, a set of caching nodes (among sick and healthy
caching nodes) broadcast information to other sick caching nodes to recover the
erased packets. The broadcast information from a caching node is assumed to be
received without any error by all other caching nodes. All the sick caching
nodes then are able to recover their erased packets, while using the broadcast
information and the nonerased packets in their storage as side information. In
this setting, if an eavesdropper overhears the broadcast channels, it might
obtain some information about the stored file. We thus study secure partial
repair in the senses of information-theoretically strong and weak security. In
both senses, we investigate the secrecy caching capacity, namely, the maximum
amount of information which can be stored in the caching network such that
there is no leakage of information during a partial repair process. We then
deduce the strong and weak secrecy caching capacities, and also derive the
sufficient finite field sizes for achieving the capacities. Finally, we propose
optimal secure codes for exact partial repair, in which the recovered packets
are exactly the same as erased packets.Comment: To Appear in IEEE Conference on Communication and Network Security
(CNS
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 and Private Cloud Storage Systems with Random Linear Fountain Codes
An information theoretic approach to security and privacy called Secure And
Private Information Retrieval (SAPIR) is introduced. SAPIR is applied to
distributed data storage systems. In this approach, random combinations of all
contents are stored across the network. Our coding approach is based on Random
Linear Fountain (RLF) codes. To retrieve a content, a group of servers
collaborate with each other to form a Reconstruction Group (RG). SAPIR achieves
asymptotic perfect secrecy if at least one of the servers within an RG is not
compromised. Further, a Private Information Retrieval (PIR) scheme based on
random queries is proposed. The PIR approach ensures the users privately
download their desired contents without the servers knowing about the requested
contents indices. The proposed scheme is adaptive and can provide privacy
against a significant number of colluding servers.Comment: 8 pages, 2 figure
Node Repair for Distributed Storage Systems over Fading Channels
Distributed storage systems and associated storage codes can efficiently
store a large amount of data while ensuring that data is retrievable in case of
node failure. The study of such systems, particularly the design of storage
codes over finite fields, assumes that the physical channel through which the
nodes communicate is error-free. This is not always the case, for example, in a
wireless storage system.
We study the probability that a subpacket is repaired incorrectly during node
repair in a distributed storage system, in which the nodes communicate over an
AWGN or Rayleigh fading channels. The asymptotic probability (as SNR increases)
that a node is repaired incorrectly is shown to be completely determined by the
repair locality of the DSS and the symbol error rate of the wireless channel.
Lastly, we propose some design criteria for physical layer coding in this
scenario, and use it to compute optimally rotated QAM constellations for use in
wireless distributed storage systems.Comment: To appear in ISITA 201
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