IACR News item: 20 August 2013
Jia Xu, Jianying Zhou
ePrint ReportWe revisit Halevi~\\emph{et al.}\'s formulation of PoW and significantly improve the understanding and construction of PoW.
Our contribution is twofold:
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First, 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}.
Based on our PoW scheme, we also construct a secure client-side deduplication method which is leakage resilient against bot outside attack and inside attack.
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Second, in order to provide a better instantiation of Privacy-Preserving-PoW, we propose a novel design of randomness extractor 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.
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