Private Information Retrieval Schemes with Regenerating Codes
A private information retrieval (PIR) scheme allows a user to retrieve a file from a database without revealing any information on the file being requested. As of now, PIR schemes have been proposed for several kinds of storage systems, including replicated and MDS-coded data. In this paper, we consider the PIR problem on optimal regenerating codes. A regenerating code is a storage code whose codewords are distributed among n nodes, enabling efficient storage of files, as well as low-bandwidth retrieval of files and repair of nodes. In this work, we propose a PIR scheme on the optimal regenerating codes constructed with the product-matrix (PM) framework of Rashmi, Shah and Kumar. We consider both minimum-bandwidth (MBR) and minimum-storage (MSR) settings, and we use the structure given by the PM framework in order to reduce the download communication complexity of our schemes.
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