Secure locally repairable codes for distributed storage systems

This paper presents coding schemes for distributed storage systems (DSS) that are secure against eavesdroppers, while simultaneously enabling efficient node repair (regeneration). Towards this, novel upper bounds on secrecy capacity for minimum storage regenerating (MSR) codes and locally repairable codes (LRCs) are derived. The eavesdropper model considered in this paper incorporates the ability to listen in on data downloaded during ℓ₂ node repairs in addition to content stored on ℓ₁ nodes. Finally, this paper presents coding schemes, based on precoding using Gabidulin codes, that achieve the upper bounds on secrecy capacity and characterize the secrecy capacity of DSS for various settings of system parameters.