1,495 research outputs found
Security in Locally Repairable Storage
In this paper we extend the notion of {\em locally repairable} codes to {\em
secret sharing} schemes. The main problem that we consider is to find optimal
ways to distribute shares of a secret among a set of storage-nodes
(participants) such that the content of each node (share) can be recovered by
using contents of only few other nodes, and at the same time the secret can be
reconstructed by only some allowable subsets of nodes. As a special case, an
eavesdropper observing some set of specific nodes (such as less than certain
number of nodes) does not get any information. In other words, we propose to
study a locally repairable distributed storage system that is secure against a
{\em passive eavesdropper} that can observe some subsets of nodes.
We provide a number of results related to such systems including upper-bounds
and achievability results on the number of bits that can be securely stored
with these constraints.Comment: This paper has been accepted for publication in IEEE Transactions of
Information Theor
New Codes and Inner Bounds for Exact Repair in Distributed Storage Systems
We study the exact-repair tradeoff between storage and repair bandwidth in
distributed storage systems (DSS). We give new inner bounds for the tradeoff
region and provide code constructions that achieve these bounds.Comment: Submitted to the IEEE International Symposium on Information Theory
(ISIT) 2014. This draft contains 8 pages and 4 figure
Secure Cooperative Regenerating Codes for Distributed Storage Systems
Regenerating codes enable trading off repair bandwidth for storage in
distributed storage systems (DSS). Due to their distributed nature, these
systems are intrinsically susceptible to attacks, and they may also be subject
to multiple simultaneous node failures. Cooperative regenerating codes allow
bandwidth efficient repair of multiple simultaneous node failures. This paper
analyzes storage systems that employ cooperative regenerating codes that are
robust to (passive) eavesdroppers. The analysis is divided into two parts,
studying both minimum bandwidth and minimum storage cooperative regenerating
scenarios. First, the secrecy capacity for minimum bandwidth cooperative
regenerating codes is characterized. Second, for minimum storage cooperative
regenerating codes, a secure file size upper bound and achievability results
are provided. These results establish the secrecy capacity for the minimum
storage scenario for certain special cases. In all scenarios, the achievability
results correspond to exact repair, and secure file size upper bounds are
obtained using min-cut analyses over a suitable secrecy graph representation of
DSS. The main achievability argument is based on an appropriate pre-coding of
the data to eliminate the information leakage to the eavesdropper
Weakly Secure Regenerating Codes for Distributed Storage
We consider the problem of secure distributed data storage under the paradigm
of \emph{weak security}, in which no \emph{meaningful information} is leaked to
the eavesdropper. More specifically, the eavesdropper cannot get any
information about any individual message file or a small group of files. The
key benefit of the weak security paradigm is that it incurs no loss in the
storage capacity, which makes it practically appealing.
In this paper, we present a coding scheme, using a coset coding based outer
code and a Product-Matrix Minimum Bandwidth Regenerating code (proposed by
Rashmi et al.) as an inner code, that achieves weak security when the
eavesdropper can observe any single storage node. We show that the proposed
construction has good security properties and requires small finite field size.Comment: Extended version of the paper accepted in NetCod 201
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