5,276 research outputs found
Secure Multiterminal Source Coding with Side Information at the Eavesdropper
The problem of secure multiterminal source coding with side information at
the eavesdropper is investigated. This scenario consists of a main encoder
(referred to as Alice) that wishes to compress a single source but
simultaneously satisfying the desired requirements on the distortion level at a
legitimate receiver (referred to as Bob) and the equivocation rate --average
uncertainty-- at an eavesdropper (referred to as Eve). It is further assumed
the presence of a (public) rate-limited link between Alice and Bob. In this
setting, Eve perfectly observes the information bits sent by Alice to Bob and
has also access to a correlated source which can be used as side information. A
second encoder (referred to as Charlie) helps Bob in estimating Alice's source
by sending a compressed version of its own correlated observation via a
(private) rate-limited link, which is only observed by Bob. For instance, the
problem at hands can be seen as the unification between the Berger-Tung and the
secure source coding setups. Inner and outer bounds on the so called
rates-distortion-equivocation region are derived. The inner region turns to be
tight for two cases: (i) uncoded side information at Bob and (ii) lossless
reconstruction of both sources at Bob --secure distributed lossless
compression. Application examples to secure lossy source coding of Gaussian and
binary sources in the presence of Gaussian and binary/ternary (resp.) side
informations are also considered. Optimal coding schemes are characterized for
some cases of interest where the statistical differences between the side
information at the decoders and the presence of a non-zero distortion at Bob
can be fully exploited to guarantee secrecy.Comment: 26 pages, 16 figures, 2 table
Secure Lossy Source Coding with Side Information at the Decoders
This paper investigates the problem of secure lossy source coding in the
presence of an eavesdropper with arbitrary correlated side informations at the
legitimate decoder (referred to as Bob) and the eavesdropper (referred to as
Eve). This scenario consists of an encoder that wishes to compress a source to
satisfy the desired requirements on: (i) the distortion level at Bob and (ii)
the equivocation rate at Eve. It is assumed that the decoders have access to
correlated sources as side information. For instance, this problem can be seen
as a generalization of the well-known Wyner-Ziv problem taking into account the
security requirements. A complete characterization of the
rate-distortion-equivocation region for the case of arbitrary correlated side
informations at the decoders is derived. Several special cases of interest and
an application example to secure lossy source coding of binary sources in the
presence of binary and ternary side informations are also considered. It is
shown that the statistical differences between the side information at the
decoders and the presence of non-zero distortion at the legitimate decoder can
be useful in terms of secrecy. Applications of these results arise in a variety
of distributed sensor network scenarios.Comment: 7 pages, 5 figures, 1 table, to be presented at Allerton 201
Secure Transmission of Sources over Noisy Channels with Side Information at the Receivers
This paper investigates the problem of source-channel coding for secure
transmission with arbitrarily correlated side informations at both receivers.
This scenario consists of an encoder (referred to as Alice) that wishes to
compress a source and send it through a noisy channel to a legitimate receiver
(referred to as Bob). In this context, Alice must simultaneously satisfy the
desired requirements on the distortion level at Bob, and the equivocation rate
at the eavesdropper (referred to as Eve). This setting can be seen as a
generalization of the problems of secure source coding with (uncoded) side
information at the decoders, and the wiretap channel. A general outer bound on
the rate-distortion-equivocation region, as well as an inner bound based on a
pure digital scheme, is derived for arbitrary channels and side informations.
In some special cases of interest, it is proved that this digital scheme is
optimal and that separation holds. However, it is also shown through a simple
counterexample with a binary source that a pure analog scheme can outperform
the digital one while being optimal. According to these observations and
assuming matched bandwidth, a novel hybrid digital/analog scheme that aims to
gather the advantages of both digital and analog ones is then presented. In the
quadratic Gaussian setup when side information is only present at the
eavesdropper, this strategy is proved to be optimal. Furthermore, it
outperforms both digital and analog schemes, and cannot be achieved via
time-sharing. By means of an appropriate coding, the presence of any
statistical difference among the side informations, the channel noises, and the
distortion at Bob can be fully exploited in terms of secrecy.Comment: To appear in IEEE Transactions on Information Theor
Privacy-Constrained Remote Source Coding
We consider the problem of revealing/sharing data in an efficient and secure
way via a compact representation. The representation should ensure reliable
reconstruction of the desired features/attributes while still preserve privacy
of the secret parts of the data. The problem is formulated as a remote lossy
source coding with a privacy constraint where the remote source consists of
public and secret parts. Inner and outer bounds for the optimal tradeoff region
of compression rate, distortion, and privacy leakage rate are given and shown
to coincide for some special cases. When specializing the distortion measure to
a logarithmic loss function, the resulting rate-distortion-leakage tradeoff for
the case of identical side information forms an optimization problem which
corresponds to the "secure" version of the so-called information bottleneck.Comment: 10 pages, 1 figure, to be presented at ISIT 201
Strongly Secure Privacy Amplification Cannot Be Obtained by Encoder of Slepian-Wolf Code
The privacy amplification is a technique to distill a secret key from a
random variable by a function so that the distilled key and eavesdropper's
random variable are statistically independent. There are three kinds of
security criteria for the key distilled by the privacy amplification: the
normalized divergence criterion, which is also known as the weak security
criterion, the variational distance criterion, and the divergence criterion,
which is also known as the strong security criterion. As a technique to distill
a secret key, it is known that the encoder of a Slepian-Wolf (the source coding
with full side-information at the decoder) code can be used as a function for
the privacy amplification if we employ the weak security criterion. In this
paper, we show that the encoder of a Slepian-Wolf code cannot be used as a
function for the privacy amplification if we employ the criteria other than the
weak one.Comment: 10 pages, no figure, A part of this paper will be presented at 2009
IEEE International Symposium on Information Theory in Seoul, Korea. Version 2
is a published version. The results are not changed from version 1.
Explanations are polished and some references are added. In version 3, only
style and DOI are edite
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