Secrecy capacity of minimum storage regenerating codes
Ankit Singh Rawat · 2017
This paper revisits the problem of designing secure minimum storage regenerating (MSR) codes for distributed storage systems (DSS). A secure MSR code ensures that a DSS does not reveal the stored information to a passive eavesdropper. The eavesdropper is assumed to have access to the content stored on ℓ1number of storage nodes in the system and the data downloaded during the bandwidth efficient repair of an additional ℓ2number of storage nodes. This paper combines the Gabidulin codes based precoding [1] and a new construction of MSR codes (without security requirements) by Ye and Barg [2] in order to obtain secure MSR codes. Such optimal secure MSR codes were previously known only in the setting where the eavesdropper was allowed to observe the repair of ℓ2nodes among a specific subset of k nodes [1], [3]. The secure coding scheme presented in this paper allows the eavesdropper to observe repair of any ℓ2out of ii nodes in the system and characterizes the secrecy capacity of linear repairable MSR codes.