Cryptology ePrint Archive: Report 2008/175

Proofs of Retrievability: Theory and Implementation

Kevin D. Bowers and Ari Juels and Alina Oprea

Abstract: A proof of retrievability (POR) is a compact proof by a file system (prover) to a client (verifier) that a target file F is intact, in the sense that the client can fully recover it. As PORs incur lower communication costs than transmission of F itself, they are an attractive building block for high-assurance remote storage systems.

In this paper, we propose a theoretical framework for the design of PORs. This framework leads to improvements in the previously proposed POR constructions of Juels-Kaliski and Shacham-Waters, and also sheds light on the conceptual limitations of previous theoretical models for PORs.

We propose a new variant on the Juels-Kaliski protocol with significantly improved efficiency and describe a prototype implementation. We demonstrate practical encoding even for files F whose size exceeds that of client main memory.

Category / Keywords: cryptographic protocols /

Date: received 16 Apr 2008

Contact author: ajuels at rsa com

Available formats: PDF | BibTeX Citation

Version: 20080421:093546 (All versions of this report)

Discussion forum: Show discussion | Start new discussion