Secure Storage using Maximally Recoverable Locally Repairable Codes

TL;DR

This paper introduces a new repair framework for maximally recoverable locally repairable codes (MR-LRCs) in distributed storage, enabling data secrecy against eavesdroppers during global repair operations.

Contribution

It proposes a novel repair framework associating local groups with central processing units, allowing nonzero secrecy dimension in MR-LRCs, and analyzes two repair schemes for enhanced security.

Findings

Secrecy dimension is positive in several parameter regimes.

The framework supports secure data storage during global repairs.

Two repair schemes, direct and forwarded, are analyzed for secrecy.

Abstract

This paper considers data secrecy in distributed storage systems (DSSs) using maximally recoverable locally repairable codes (MR-LRCs). Conventional MR-LRCs are in general not secure against eavesdroppers who can observe the transmitted data during a global repair operation. This work enables nonzero secrecy dimension of DSSs encoded by MR-LRCs through a new repair framework. The key idea is to associate each local group with a central processing unit (CPU), which aggregates and transmits the contribution from the intact nodes of their group to the CPU of a group needing a global repair. The aggregation is enabled by so-called local polynomials that can be generated independently in each group. Two different schemes -- direct repair and forwarded repair -- are considered, and their secrecy dimension using MR-LRCs is derived. Positive secrecy dimension is enabled for several parameter regimes.