3,187 research outputs found
Secure Multiplex Coding with a Common Message
We determine the capacity region of the secure multiplex coding with a common
message, and evaluate the mutual information and the equivocation rate of a
collection of secret messages to the second receiver (eavesdropper), which were
not evaluated by Yamamoto et al.Comment: 5 pages, no figure, IEEEtran.sty, final version to appear in Proc.
ISIT 201
Universal Secure Multiplex Network Coding with Dependent and Non-Uniform Messages
We consider the random linear precoder at the source node as a secure network
coding. We prove that it is strongly secure in the sense of Harada and Yamamoto
and universal secure in the sense of Silva and Kschischang, while allowing
arbitrary small but nonzero mutual information to the eavesdropper. Our
security proof allows statistically dependent and non-uniform multiple secret
messages, while all previous constructions of weakly or strongly secure network
coding assumed independent and uniform messages, which are difficult to be
ensured in practice.Comment: 10 pages, 1 figure, IEEEtrans.cls. Online published in IEEE Trans.
Inform. Theor
Secure Multiplex Coding with Dependent and Non-Uniform Multiple Messages
The secure multiplex coding (SMC) is a technique to remove rate loss in the
coding for wire-tap channels and broadcast channels with confidential messages
caused by the inclusion of random bits into transmitted signals. SMC replaces
the random bits by other meaningful secret messages, and a collection of secret
messages serves as the random bits to hide the rest of messages. In the
previous researches, multiple secret messages were assumed to have independent
and uniform distributions, which is difficult to be ensured in practice. We
remove this restrictive assumption by a generalization of the channel
resolvability technique.
We also give practical construction techniques for SMC by using an arbitrary
given error-correcting code as an ingredient, and channel-universal coding of
SMC. By using the same principle as the channel-universal SMC, we give coding
for the broadcast channel with confidential messages universal to both channel
and source distributions.Comment: We made several changes to improve the presentatio
Coding Schemes for Achieving Strong Secrecy at Negligible Cost
We study the problem of achieving strong secrecy over wiretap channels at
negligible cost, in the sense of maintaining the overall communication rate of
the same channel without secrecy constraints. Specifically, we propose and
analyze two source-channel coding architectures, in which secrecy is achieved
by multiplexing public and confidential messages. In both cases, our main
contribution is to show that secrecy can be achieved without compromising
communication rate and by requiring only randomness of asymptotically vanishing
rate. Our first source-channel coding architecture relies on a modified wiretap
channel code, in which randomization is performed using the output of a source
code. In contrast, our second architecture relies on a standard wiretap code
combined with a modified source code termed uniform compression code, in which
a small shared secret seed is used to enhance the uniformity of the source code
output. We carry out a detailed analysis of uniform compression codes and
characterize the optimal size of the shared seed.Comment: 15 pages, two-column, 5 figures, accepted to IEEE Transactions on
Information Theor
Secure Multiplex Coding Over Interference Channel with Confidential Messages
In this paper, inner and outer bounds on the capacity region of two-user
interference channels with two confidential messages have been proposed. By
adding secure multiplex coding to the error correction method in [15] which
achieves the best achievable capacity region for interference channel up to
now, we have shown that the improved secure capacity region compared with [2]
now is the whole Han-Kobayashi region. In addition, this construction not only
removes the rate loss incurred by adding dummy messages to achieve security,
but also change the original weak security condition in [2] to strong security.
Then the equivocation rate for a collection of secret messages has also been
evaluated, when the length of the message is finite or the information rate is
high, our result provides a good approximation for bounding the worst case
equivocation rate. Our results can be readily extended to the Gaussian
interference channel with little efforts.Comment: 10 pages, 6 figure
Finite-Block-Length Analysis in Classical and Quantum Information Theory
Coding technology is used in several information processing tasks. In
particular, when noise during transmission disturbs communications, coding
technology is employed to protect the information. However, there are two types
of coding technology: coding in classical information theory and coding in
quantum information theory. Although the physical media used to transmit
information ultimately obey quantum mechanics, we need to choose the type of
coding depending on the kind of information device, classical or quantum, that
is being used. In both branches of information theory, there are many elegant
theoretical results under the ideal assumption that an infinitely large system
is available. In a realistic situation, we need to account for finite size
effects. The present paper reviews finite size effects in classical and quantum
information theory with respect to various topics, including applied aspects
Quantum Cryptography II: How to re-use a one-time pad safely even if P=NP
When elementary quantum systems, such as polarized photons, are used to
transmit digital information, the uncertainty principle gives rise to novel
cryptographic phenomena unachievable with traditional transmission media, e.g.
a communications channel on which it is impossible in principle to eavesdrop
without a high probability of being detected. With such a channel, a one-time
pad can safely be reused many times as long as no eavesdrop is detected, and,
planning ahead, part of the capacity of these uncompromised transmissions can
be used to send fresh random bits with which to replace the one-time pad when
an eavesdrop finally is detected. Unlike other schemes for stretching a
one-time pad, this scheme does not depend on complexity-theoretic assumptions
such as the difficulty of factoring.Comment: Original 1982 submission to ACM Symposium on Theory of Computing with
spelling and typographical corrections, and comments by the authors 32 years
later. Submitted to Natural Computin
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