\begin{itemize} \item
Firstly, we propose a generic and conceptually simple approach to construct \emph{Privacy-Preserving} Proofs of Ownership scheme, by leveraging on well-known primitives (i.e. Randomness Extractor and Proofs of Retrievability) and technique (i.e. sample-then-extract). Our approach can be roughly described as \textsf{Privacy-Preserving PoW = Randomness Extractor $+$ Proofs of Retrievability}.
\item Secondly, in order to provide a better instantiation of Privacy-Preserving-PoW, we propose a novel design of randomness extractor with large output size, which improves the state of art by reducing both the random seed length and entropy loss (i.e. the difference between the entropy of input and output) simultaneously. \end{itemize}
Category / Keywords: cryptographic protocols / Cloud Storage, Client-side Deduplication, Proofs of Ownership, Leakage Resilience, Privacy-Preserving, Proofs of Retrievability, Randomness Extractor, Sample-then-Extract Date: received 18 Aug 2013, last revised 27 Mar 2014 Contact author: jiaxu2001 at gmail com Available format(s): PDF | BibTeX Citation Note: Significant revision in writing. A short version of this work is accepted by ACNS '14. Version: 20140328:022136 (All versions of this report) Short URL: ia.cr/2013/514