2018 IEEE Symposium on Security and Privacy (SP) (2018)

San Francisco, CA, US

May 21, 2018 to May 23, 2018

ISSN: 2375-1207

ISBN: 978-1-5386-4353-2

pp: 975-992

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/SP.2018.00060

Riad S. Wahby , Stanford University

Ioanna Tzialla , New York University

abhi shelat , Northeastern University

Justin Thaler , Georgetown University

Michael Walfish , New York University

ABSTRACT

We present a zero-knowledge argument for NP with low communication complexity,
low concrete cost for both the prover and the verifier, and no trusted setup,
based on standard cryptographic assumptions. Communication is proportional
to d log G (for d the depth and G the width of the verifying circuit) plus
the square root of the witness size. When applied to batched or data-parallel
statements, the prover's runtime is linear and the verifier's is sub-linear
in the verifying circuit size, both with good constants. In addition,
witness-related communication can be reduced, at the cost of increased
verifier runtime, by leveraging a new commitment scheme for multilinear
polynomials, which may be of independent interest. These properties represent
a new point in the tradeoffs among setup, complexity assumptions, proof size,
and computational cost.
We apply the Fiat-Shamir heuristic to this argument to produce a zero-knowledge
succinct non-interactive argument of knowledge (zkSNARK) in the random oracle
model, based on the discrete log assumption, which we call Hyrax. We implement
Hyrax and evaluate it against five state-of-the-art baseline systems. Our
evaluation shows that, even for modest problem sizes, Hyrax gives smaller
proofs than all but the most computationally costly baseline, and that its
prover and verifier are each faster than three of the five baselines.

INDEX TERMS

cryptographic-protocols, zero-knowledge, succinct-arguments, computationally-sound-proofs

CITATION

R. S. Wahby, I. Tzialla, a. shelat, J. Thaler and M. Walfish, "Doubly-efficient zkSNARKs without trusted setup,"

*2018 IEEE Symposium on Security and Privacy (SP)*, San Francisco, CA, US, , pp. 975-992.

doi:10.1109/SP.2018.00060