52 research outputs found
Beyond Countable Alphabets: An Extension of the Information-Spectrum Approach
A general approach is established for deriving one-shot performance bounds
for information-theoretic problems on general alphabets beyond countable
alphabets. It is mainly based on the quantization idea and a novel form of
"likelihood ratio". As an example, one-shot lower and upper bounds for random
number generation from correlated sources on general alphabets are derived.Comment: v0.5.1.20be8d, 7 page
On the Capacity Region for Secure Index Coding
We study the index coding problem in the presence of an eavesdropper, where
the aim is to communicate without allowing the eavesdropper to learn any single
message aside from the messages it may already know as side information. We
establish an outer bound on the underlying secure capacity region of the index
coding problem, which includes polymatroidal and security constraints, as well
as the set of additional decoding constraints for legitimate receivers. We then
propose a secure variant of the composite coding scheme, which yields an inner
bound on the secure capacity region of the index coding problem. For the
achievability of secure composite coding, a secret key with vanishingly small
rate may be needed to ensure that each legitimate receiver who wants the same
message as the eavesdropper, knows at least two more messages than the
eavesdropper. For all securely feasible index coding problems with four or
fewer messages, our numerical results establish the secure index coding
capacity region
Fixed-Length Strong Coordination
We consider the problem of synthesizing joint distributions of signals and
actions over noisy channels in the finite-length regime. For a fixed
blocklength and an upper bound on the distance , a coding
scheme is proposed such that the induced joint distribution is
-close in distance to a target i.i.d. distribution. The set
of achievable target distributions and rate for asymptotic strong coordination
can be recovered from the main result of this paper by having that tends to
infinity.Comment: 5 pages, 2 figure
Secure Strong Coordination
We consider a network of two nodes separated by a noisy channel, in which the
source and its reconstruction have to be strongly coordinated, while
simultaneously satisfying the strong secrecy condition with respect to an
outside observer of the noisy channel. In the case of non-causal encoding and
decoding, we propose a joint source-channel coding scheme for the secure strong
coordination region. Furthermore, we provide a complete characterization of the
secure strong coordination region when the decoder has to reliably reconstruct
the source sequence and the legitimate channel is more capable than the channel
of the eavesdropper
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