9,476 research outputs found
Universal secure rank-metric coding schemes with optimal communication overheads
We study the problem of reducing the communication overhead from a noisy
wire-tap channel or storage system where data is encoded as a matrix, when more
columns (or their linear combinations) are available. We present its
applications to reducing communication overheads in universal secure linear
network coding and secure distributed storage with crisscross errors and
erasures and in the presence of a wire-tapper. Our main contribution is a
method to transform coding schemes based on linear rank-metric codes, with
certain properties, to schemes with lower communication overheads. By applying
this method to pairs of Gabidulin codes, we obtain coding schemes with optimal
information rate with respect to their security and rank error correction
capability, and with universally optimal communication overheads, when , being and the number of columns and number of rows,
respectively. Moreover, our method can be applied to other families of maximum
rank distance codes when . The downside of the method is generally
expanding the packet length, but some practical instances come at no cost.Comment: 21 pages, LaTeX; parts of this paper have been accepted for
presentation at the IEEE International Symposium on Information Theory,
Aachen, Germany, June 201
New Parameters of Linear Codes Expressing Security Performance of Universal Secure Network Coding
The universal secure network coding presented by Silva et al. realizes secure
and reliable transmission of a secret message over any underlying network code,
by using maximum rank distance codes. Inspired by their result, this paper
considers the secure network coding based on arbitrary linear codes, and
investigates its security performance and error correction capability that are
guaranteed independently of the underlying network code. The security
performance and error correction capability are said to be universal when they
are independent of underlying network codes. This paper introduces new code
parameters, the relative dimension/intersection profile (RDIP) and the relative
generalized rank weight (RGRW) of linear codes. We reveal that the universal
security performance and universal error correction capability of secure
network coding are expressed in terms of the RDIP and RGRW of linear codes. The
security and error correction of existing schemes are also analyzed as
applications of the RDIP and RGRW.Comment: IEEEtran.cls, 8 pages, no figure. To appear in Proc. 50th Annual
Allerton Conference on Communication, Control, and Computing (Allerton 2012).
Version 2 added an exact expression of the universal error correction
capability in terms of the relative generalized rank weigh
Network Codes Resilient to Jamming and Eavesdropping
We consider the problem of communicating information over a network secretly
and reliably in the presence of a hidden adversary who can eavesdrop and inject
malicious errors. We provide polynomial-time, rate-optimal distributed network
codes for this scenario, improving on the rates achievable in previous work.
Our main contribution shows that as long as the sum of the adversary's jamming
rate Zo and his eavesdropping rate Zi is less than the network capacity C,
(i.e., Zo+Zi<C), our codes can communicate (with vanishingly small error
probability) a single bit correctly and without leaking any information to the
adversary. We then use this to design codes that allow communication at the
optimal source rate of C-Zo-Zi, while keeping the communicated message secret
from the adversary. Interior nodes are oblivious to the presence of adversaries
and perform random linear network coding; only the source and destination need
to be tweaked. In proving our results we correct an error in prior work by a
subset of the authors in this work.Comment: 6 pages, to appear at IEEE NetCod 201
Relative Generalized Rank Weight of Linear Codes and Its Applications to Network Coding
By extending the notion of minimum rank distance, this paper introduces two
new relative code parameters of a linear code C_1 of length n over a field
extension and its subcode C_2. One is called the relative
dimension/intersection profile (RDIP), and the other is called the relative
generalized rank weight (RGRW). We clarify their basic properties and the
relation between the RGRW and the minimum rank distance. As applications of the
RDIP and the RGRW, the security performance and the error correction capability
of secure network coding, guaranteed independently of the underlying network
code, are analyzed and clarified. We propose a construction of secure network
coding scheme, and analyze its security performance and error correction
capability as an example of applications of the RDIP and the RGRW. Silva and
Kschischang showed the existence of a secure network coding in which no part of
the secret message is revealed to the adversary even if any dim C_1-1 links are
wiretapped, which is guaranteed over any underlying network code. However, the
explicit construction of such a scheme remained an open problem. Our new
construction is just one instance of secure network coding that solves this
open problem.Comment: IEEEtran.cls, 25 pages, no figure, accepted for publication in IEEE
Transactions on Information Theor
Generalized weights: an anticode approach
In this paper we study generalized weights as an algebraic invariant of a
code. We first describe anticodes in the Hamming and in the rank metric,
proving in particular that optimal anticodes in the rank metric coincide with
Frobenius-closed spaces. Then we characterize both generalized Hamming and rank
weights of a code in terms of the intersection of the code with optimal
anticodes in the respective metrics. Inspired by this description, we propose a
new algebraic invariant, which we call "Delsarte generalized weights", for
Delsarte rank-metric codes based on optimal anticodes of matrices. We show that
our invariant refines the generalized rank weights for Gabidulin codes proposed
by Kurihara, Matsumoto and Uyematsu, and establish a series of properties of
Delsarte generalized weights. In particular, we characterize Delsarte optimal
codes and anticodes in terms of their generalized weights. We also present a
duality theory for the new algebraic invariant, proving that the Delsarte
generalized weights of a code completely determine the Delsarte generalized
weights of the dual code. Our results extend the theory of generalized rank
weights for Gabidulin codes. Finally, we prove the analogue for Gabidulin codes
of a theorem of Wei, proving that their generalized rank weights characterize
the worst-case security drops of a Gabidulin rank-metric code
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