7,459 research outputs found
Micro protocol engineering for unstructured carriers: On the embedding of steganographic control protocols into audio transmissions
Network steganography conceals the transfer of sensitive information within
unobtrusive data in computer networks. So-called micro protocols are
communication protocols placed within the payload of a network steganographic
transfer. They enrich this transfer with features such as reliability, dynamic
overlay routing, or performance optimization --- just to mention a few. We
present different design approaches for the embedding of hidden channels with
micro protocols in digitized audio signals under consideration of different
requirements. On the basis of experimental results, our design approaches are
compared, and introduced into a protocol engineering approach for micro
protocols.Comment: 20 pages, 7 figures, 4 table
Blind Reconciliation
Information reconciliation is a crucial procedure in the classical
post-processing of quantum key distribution (QKD). Poor reconciliation
efficiency, revealing more information than strictly needed, may compromise the
maximum attainable distance, while poor performance of the algorithm limits the
practical throughput in a QKD device. Historically, reconciliation has been
mainly done using close to minimal information disclosure but heavily
interactive procedures, like Cascade, or using less efficient but also less
interactive -just one message is exchanged- procedures, like the ones based in
low-density parity-check (LDPC) codes. The price to pay in the LDPC case is
that good efficiency is only attained for very long codes and in a very narrow
range centered around the quantum bit error rate (QBER) that the code was
designed to reconcile, thus forcing to have several codes if a broad range of
QBER needs to be catered for. Real world implementations of these methods are
thus very demanding, either on computational or communication resources or
both, to the extent that the last generation of GHz clocked QKD systems are
finding a bottleneck in the classical part. In order to produce compact, high
performance and reliable QKD systems it would be highly desirable to remove
these problems. Here we analyse the use of short-length LDPC codes in the
information reconciliation context using a low interactivity, blind, protocol
that avoids an a priori error rate estimation. We demonstrate that 2x10^3 bits
length LDPC codes are suitable for blind reconciliation. Such codes are of high
interest in practice, since they can be used for hardware implementations with
very high throughput.Comment: 22 pages, 8 figure
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,
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