Concurrent zero-knowledge

@article{Dwork2004ConcurrentZ,
  title={Concurrent zero-knowledge},
  author={Cynthia Dwork and Moni Naor and Amit Sahai},
  journal={IACR Cryptol. ePrint Arch.},
  year={2004},
  volume={1999},
  pages={23}
}
Concurrent executions of a zero-knowledge protocol by a single prover (with one or more verifiers) may leak information and may not be zero-knowledge <i>in toto</i>. In this article, we study the problem of maintaining zero-knowledge.We introduce the notion of an (α, β) <i>timing constraint</i>: for any two processors <i>P</i><sub>1</sub> and <i>P</i><sub>2</sub>, if <i>P</i><sub>1</sub> measures α elapsed time on its local clock and <i>P</i><sub>2</sub> measures β elapsed time on its local… 

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References

SHOWING 1-10 OF 73 REFERENCES

Concurrent zero-knowledge

Concurrent executions of a zero-knowledge protocol by a ainSle prover (with one or more verifiers) may leak information and may not be zero-knowledge in toto; for example, in the case of

Concurrent and resettable zero-knowledge in poly-loalgorithm rounds

TLDR
This paper presents a concurrent zero-knowledge proof for all languages in NP with a poly-logarithmic round complexity: specifically, ω(log^2 <italic>k</italic>) rounds given at most k concurrent proofs, and shows that a simple modification of the proof is a resettable zero- knowledge proof for NP.

Concurrent Zero-Knowledge: Reducing the Need for Timing Constraints

TLDR
A preprocessing protocol is designed, making use of timing, to simulate the trusted center for the purposes of achieving concurrent zero-knowledge, and any polynomial number of subsequent executions of a rich class of protocols will be concurrentZeroknowledge.

On Concurrent Zero-Knowledge with Pre-processing

TLDR
This paper shows an efficient constant-round concurrent zero-knowledge protocol with preprocessing for all languages in NP, where both the preprocessing phase and the proof phase each require 3 rounds of interaction.

Concurrent Zero-Knowledge in Poly-logarithmic Rounds

TLDR
This paper presents a concurrent zero-knowledge proof for all languages in NP with a drastically improved complexity: the proof requires only a poly-logarithmic, specifically, ω(log2 k) number of rounds.

Completeness theorems for non-cryptographic fault-tolerant distributed computation

Every function of <italic>n</italic> inputs can be efficiently computed by a complete network of <italic>n</italic> processors in such a way that:<list><item>If no faults occur, no set of size

A Note on the Round-Complexity of Concurrent Zero-Knowledge

TLDR
It is shown that in the context of Concurrent Zero-Knowledge, at least eight rounds of interaction are essential for black-box simulation of non-trivial proof systems (i.e., systems for languages that are not in BPP).

Concurrent zero knowledge with logarithmic round-complexity

TLDR
It is shown that every language in NP has a (black-box) concurrent zero-knowledge proof system using O/spl tilde/(log n) rounds of interaction, and the zero- knowledge property of the main protocol is proved under the assumption that there exists a collection of claw free functions.

Black-Box Concurrent Zero-Knowledge Requires (Almost) Logarithmically Many Rounds

TLDR
It is shown that any concurrent zero-knowledge protocol for a nontrivial language must use at least $\tilde\Omega(\log n)$ rounds of interaction, which is the first bound to rule out the possibility of constant-round concurrentzero-knowledge when proven via black-box simulation.

On the Composition of Zero-Knowledge Proof Systems

TLDR
It is proved that three-round interactive proofs and constant-round Arthur--Merlin proofs that are black-box simulation zero-knowledge exist only for languages in BPP, and it follows that the "parallel versions" of the first interactive proofs systems presented for quadratic residuosity, graph isomorphism, and any language in NP, are not black- box simulationzero-knowledge, unless the corresponding languages are in B PP.
...