Capacity and Security of Heterogeneous Distributed Storage Systems

Abstract

We study the capacity of heterogeneous distributed storage systems under repair dynamics. Examples of these systems include peer-to-peer storage clouds, wireless, and Internet caching systems. Nodes in a heterogeneous system can have different storage capacities and different repair bandwidths. We give lower and upper bounds on the system capacity. These bounds depend on either the average resources per node, or on a detailed knowledge of the node characteristics. Moreover, we study the case in which nodes may be compromised by an eavesdropper, and give bounds on the system secrecy capacity. One implication of our results is that symmetric repair maximizes the capacity of a homogeneous system, which justifies the model widely used in the literature.

Efficiently sphere-decodable physical layer transmission schemes for wireless storage networks

“…13, we illustrate the overall picture for the case of n t = 1, n r = 2, and K = 10. While we do not yet have a lower bound or a tight DMT result, we believe that Scheme 3 is indeed likely to be superior 10 to all other schemes presented in this paper, namely the TDMA scheme, Schemes 1 and 2.…”

“…[8,9]. for details), and codes lying on the storage-repair bandwidth tradeoff curve [8,10] are called regenerating codes. Explicit, tradeoff achieving regenerating codes can be found in the literature, see [9,11], among others.…”

“…9 Here we have implicitly assumed K − L ≥ 1 such that at least one helper node will function as a relay. 10 Cf. the corresponding upper bound d 2,U (r) = d 2 (r) for Scheme 3 that turned out to be tight.…”

Information-Theoretically Secure Erasure Codes for Distributed Storage

“…Subsequent to the initial presentation of our codes in [1], there have been several other works on information theoretic security in distributed storage systems with repair considerations ( [48], [60]- [63]). In [48], the authors consider security from passive eavesdroppers and present outer bounds for the MSR setting that are tighter than those proposed in [33].…”

“…For these parameters, it is shown that MBR is the one and only regime for which the resource requirements in the system do not increase when, in addition to security from an eavesdropper being able to read data stored in nodes, security from an eavesdropper who can also tap on to the data downloaded during repair is desired. Security in distributed storage systems with heterogeneous storage nodes is considered in [63].…”