### QuickSilver: Efficient and Affordable Zero-Knowledge Proofs for Circuits and Polynomials over Any Field

Kang Yang, Pratik Sarkar, Chenkai Weng, and Xiao Wang

##### Abstract

Zero-knowledge (ZK) proofs with an optimal memory footprint have attracted a lot of attention, because such protocols can easily prove very large computation with a small memory requirement. Such ZK protocol only needs O(M) memory for both parties, where M is the memory required to verify the statement in the clear. In this paper, we propose several new ZK protocols in this setting, which improve the concrete efficiency and, at the same time, enable sublinear amortized communication for circuits with some notion of relaxed uniformity. 1. In the circuit-based model, where the computation is represented as a circuit over a field, our ZK protocol achieves a communication complexity of 1 field element per non-linear gate for any field size while keeping the computation very cheap. We implemented our protocol, which shows extremely high efficiency and affordability. Compared to the previous best-known implementation, we achieve 6×–7× improvement in computation and 3×– 7× improvement in communication. When running on intro-level AWS instances, our protocol only needs one US dollar to prove one trillion AND gates (or 2.5 US dollars for one trillion multiplication gates over a 61-bit field). 2. In the setting where part of the computation can be represented as a set of polynomials, we can achieve communication sublinear to the polynomial size: the communication only depends on the input size and the highest degree of all polynomials, independent of the number of polynomials and the number of multiplications in the polynomials. Using the improved ZK protocol, we can prove matrix multiplication with communication proportional to the input size, rather than the number of multiplications. Proving the multiplication of two 1024 × 1024 matrices, our implementation, with one thread and 1 GB of memory, only needs 10 seconds and communicates 25 MB, 35× faster than the state-of-the-art protocol Virgo that would need more than 140 GB of memory for the same task.

Available format(s)
Category
Cryptographic protocols
Publication info
Published elsewhere. MINOR revision.ACM CCS 2021
DOI
10.1145/3460120.3484556
Keywords
zero-knowledge proof
Contact author(s)
wangxiao @ cs northwestern edu
History
2021-09-11: last of 2 revisions
See all versions
Short URL
https://ia.cr/2021/076

CC BY

BibTeX

@misc{cryptoeprint:2021/076,
author = {Kang Yang and Pratik Sarkar and Chenkai Weng and Xiao Wang},
title = {QuickSilver: Efficient and Affordable Zero-Knowledge Proofs for Circuits and Polynomials over Any Field},
howpublished = {Cryptology ePrint Archive, Paper 2021/076},
year = {2021},
doi = {10.1145/3460120.3484556},
note = {\url{https://eprint.iacr.org/2021/076}},
url = {https://eprint.iacr.org/2021/076}
}

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