833 research outputs found
Optimal Locally Repairable and Secure Codes for Distributed Storage Systems
This paper aims to go beyond resilience into the study of security and
local-repairability for distributed storage systems (DSS). Security and
local-repairability are both important as features of an efficient storage
system, and this paper aims to understand the trade-offs between resilience,
security, and local-repairability in these systems. In particular, this paper
first investigates security in the presence of colluding eavesdroppers, where
eavesdroppers are assumed to work together in decoding stored information.
Second, the paper focuses on coding schemes that enable optimal local repairs.
It further brings these two concepts together, to develop locally repairable
coding schemes for DSS that are secure against eavesdroppers.
The main results of this paper include: a. An improved bound on the secrecy
capacity for minimum storage regenerating codes, b. secure coding schemes that
achieve the bound for some special cases, c. a new bound on minimum distance
for locally repairable codes, d. code construction for locally repairable codes
that attain the minimum distance bound, and e. repair-bandwidth-efficient
locally repairable codes with and without security constraints.Comment: Submitted to IEEE Transactions on Information Theor
Secure Repairable Fountain Codes
In this letter, we provide the construction of repairable fountain codes
(RFCs) for distributed storage systems that are information-theoretically
secure against an eavesdropper that has access to the data stored in a subset
of the storage nodes and the data downloaded to repair an additional subset of
storage nodes. The security is achieved by adding random symbols to the
message, which is then encoded by the concatenation of a Gabidulin code and an
RFC. We compare the achievable code rates of the proposed codes with those of
secure minimum storage regenerating codes and secure locally repairable codes.Comment: To appear in IEEE Communications Letter
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
Optimal Locally Repairable Codes via Rank-Metric Codes
This paper presents a new explicit construction for locally repairable codes
(LRCs) for distributed storage systems which possess all-symbols locality and
maximal possible minimum distance, or equivalently, can tolerate the maximal
number of node failures. This construction, based on maximum rank distance
(MRD) Gabidulin codes, provides new optimal vector and scalar LRCs. In
addition, the paper also discusses mechanisms by which codes obtained using
this construction can be used to construct LRCs with efficient repair of failed
nodes by combination of LRC with regenerating codes
Two-layer Locally Repairable Codes for Distributed Storage Systems
In this paper, we propose locally repairable codes (LRCs) with optimal
minimum distance for distributed storage systems (DSS). A two-layer encoding
structure is employed to ensure data reconstruction and the designated repair
locality. The data is first encoded in the first layer by any existing maximum
distance separable (MDS) codes, and then the encoded symbols are divided into
non-overlapping groups and encoded by an MDS array code in the second layer.
The encoding in the second layer provides enough redundancy for local repair,
while the overall code performs recovery of the data based on redundancy from
both layers. Our codes can be constructed over a finite field with size growing
linearly with the total number of nodes in the DSS, and facilitate efficient
degraded reads.Comment: This paper has been withdrawn by the author due to inaccuracy of
Claim
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