### Non-black-box Simulation in the Fully Concurrent Setting, Revisited

Susumu Kiyoshima

##### Abstract

We give a new proof of the existence of $O(n^{\epsilon})$-round public-coin concurrent zero-knowledge arguments for NP, where $\epsilon>0$ is an arbitrary constant. The security is proven in the plain model under the assumption that collision-resistant hash functions exist. (The existence of such concurrent zero-knowledge arguments was previously proven by Goyal (STOC'13) in the plain model under the same assumption.) In the proof, we use a new variant of the non-black-box simulation technique of Barak (FOCS'01). An important property of our simulation technique is that the simulator runs in a "straight-line" manner in the fully concurrent setting. Compared with the simulation technique of Goyal, which also has such a property, the analysis of our simulation technique is (arguably) simpler.

Note: This article is based on an earlier article: An Alternative Approach to Non-black-box Simulation in Fully Concurrent Setting, in Proceedings of TCC 2015, DOI: 10.1007/978-3-662-46494-6_13. The main result remains the same as before.

Available format(s)
Category
Foundations
Publication info
DOI
10.1007/s00145-018-09309-5
Keywords
concurrent zero-knowledgenon-black-box simulation
Contact author(s)
susumu @ kiyoshima info
History
2019-03-14: last of 2 revisions
See all versions
Short URL
https://ia.cr/2015/067

CC BY

BibTeX

@misc{cryptoeprint:2015/067,
author = {Susumu Kiyoshima},
title = {Non-black-box Simulation in the Fully Concurrent Setting, Revisited},
howpublished = {Cryptology ePrint Archive, Paper 2015/067},
year = {2015},
doi = {10.1007/s00145-018-09309-5},
note = {\url{https://eprint.iacr.org/2015/067}},
url = {https://eprint.iacr.org/2015/067}
}

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