1,043 research outputs found
Multilevel Diversity Coding with Secure Regeneration: Separate Coding Achieves the MBR Point
The problem of multilevel diversity coding with secure regeneration (MDC-SR)
is considered, which includes the problems of multilevel diversity coding with
regeneration (MDC-R) and secure regenerating code (SRC) as special cases. Two
outer bounds are established, showing that separate coding of different
messages using the respective SRCs can achieve the
minimum-bandwidth-regeneration (MBR) point of the achievable normalized
storage-capacity repair-bandwidth tradeoff regions for the general MDC-SR
problem. The core of the new converse results is an exchange lemma, which can
be established using Han's subset inequality
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
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