3,596 research outputs found
Algebraic Watchdog: Mitigating Misbehavior in Wireless Network Coding
We propose a secure scheme for wireless network coding, called the algebraic
watchdog. By enabling nodes to detect malicious behaviors probabilistically and
use overheard messages to police their downstream neighbors locally, the
algebraic watchdog delivers a secure global self-checking network. Unlike
traditional Byzantine detection protocols which are receiver-based, this
protocol gives the senders an active role in checking the node downstream. The
key idea is inspired by Marti et al.'s watchdog-pathrater, which attempts to
detect and mitigate the effects of routing misbehavior.
As an initial building block of a such system, we first focus on a two-hop
network. We present a graphical model to understand the inference process nodes
execute to police their downstream neighbors; as well as to compute, analyze,
and approximate the probabilities of misdetection and false detection. In
addition, we present an algebraic analysis of the performance using an
hypothesis testing framework that provides exact formulae for probabilities of
false detection and misdetection.
We then extend the algebraic watchdog to a more general network setting, and
propose a protocol in which we can establish trust in coded systems in a
distributed manner. We develop a graphical model to detect the presence of an
adversarial node downstream within a general multi-hop network. The structure
of the graphical model (a trellis) lends itself to well-known algorithms, such
as the Viterbi algorithm, which can compute the probabilities of misdetection
and false detection. We show analytically that as long as the min-cut is not
dominated by the Byzantine adversaries, upstream nodes can monitor downstream
neighbors and allow reliable communication with certain probability. Finally,
we present simulation results that support our analysis.Comment: 10 pages, 10 figures, Submitted to IEEE Journal on Selected Areas in
Communications (JSAC) "Advances in Military Networking and Communications
Double-Directional Information Azimuth Spectrum and Relay Network Tomography for a Decentralized Wireless Relay Network
A novel channel representation for a two-hop decentralized wireless relay
network (DWRN) is proposed, where the relays operate in a completely
distributive fashion. The modeling paradigm applies an analogous approach to
the description method for a double-directional multipath propagation channel,
and takes into account the finite system spatial resolution and the extended
relay listening/transmitting time. Specifically, the double-directional
information azimuth spectrum (IAS) is formulated to provide a compact
representation of information flows in a DWRN. The proposed channel
representation is then analyzed from a geometrically-based statistical modeling
perspective. Finally, we look into the problem of relay network tomography
(RNT), which solves an inverse problem to infer the internal structure of a
DWRN by using the instantaneous doubledirectional IAS recorded at multiple
measuring nodes exterior to the relay region
A Multi-hop Multi-source Algebraic Watchdog
In our previous work "An Algebraic Watchdog for Wireless Network Coding", we
proposed a new scheme in which nodes can detect malicious behaviors
probabilistically, police their downstream neighbors locally using overheard
messages; thus, provide a secure global "self-checking network". As the first
building block of such a system, we focused on a two-hop network, and presented
a graphical model to understand the inference process by which nodes police
their downstream neighbors and to compute the probabilities of misdetection and
false detection.
In this paper, we extend the Algebraic Watchdog to a more general network
setting, and propose a protocol in which we can establish "trust" in coded
systems in a distributed manner. We develop a graphical model to detect the
presence of an adversarial node downstream within a general two-hop network.
The structure of the graphical model (a trellis) lends itself to well-known
algorithms, such as Viterbi algorithm, that can compute the probabilities of
misdetection and false detection. Using this as a building block, we generalize
our scheme to multi-hop networks. We show analytically that as long as the
min-cut is not dominated by the Byzantine adversaries, upstream nodes can
monitor downstream neighbors and allow reliable communication with certain
probability. Finally, we present preliminary simulation results that support
our analysis.Comment: 5 pages, 2 figures, to appear in IEEE ITW Dublin 201
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