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Paper: Precise Zero-Knowledge in Concurrent Setting

Authors:
Ning Ding
Dawu Gu
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URL: http://eprint.iacr.org/2007/456
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Abstract: We present a stronger notion of zero-knowledge: precise concurrent zero-knowledge. Our notion captures the idea that the view of any verifier in concurrent interaction can be reconstructed in the almost same time (within a constant/polynomial factor). Precise zero-knowledge in stand-alone setting was introduced by Micali and Pass in STOC'06 (The original work used the term "local zero-knowledge".). Their notion shows that the view of any verifier can be reconstructed in the almost same time in stand-alone setting. Hence our notion is the generalization of their notion in concurrent setting. Furthermore, we propose a $\omega (\log ^2 n)$-round concurrent zero-knowledge argument for ${\rm{NP}}$ with linear precision, which shows that the view of any verifier in concurrent interaction can be reconstructed by the simulator with linear-time overhead. Our argument is Feige-Lapidot-Shamir type which consists of a proof-preamble and a proof-body for a modified NP statement. Our result assumes the restriction of adversarial scheduling the communication that the concurrent interaction of preambles of all sessions will be scheduled before any proof-body by the adversarial verifier.
BibTeX
@misc{eprint-2007-13736,
  title={Precise Zero-Knowledge in Concurrent Setting},
  booktitle={IACR Eprint archive},
  keywords={foundations /},
  url={http://eprint.iacr.org/2007/456},
  note={ dingning@sjtu.edu.cn 13855 received 7 Dec 2007},
  author={Ning Ding and Dawu Gu},
  year=2007
}