Date Added: Oct 2012
Regenerating codes enable trading off repair bandwidth for storage in Distributed Storage Systems (DSS). Due to their distributed nature, these systems are intrinsically susceptible to attacks, and they may be susceptible to multiple node failures. This paper analyzes storage systems that employ cooperative regenerating codes that are robust to (passive) eavesdroppers. The analysis is divided into two parts, studying both minimum bandwidth and minimum storage cooperative regenerating scenarios. First, the secrecy capacity of minimum bandwidth cooperative regenerating codes is characterized. Second, for minimum storage cooperative regenerating codes, a secure file size upper bound and achievability results are provided. These results establish the secrecy capacity for the minimum storage scenario for certain special cases.