Paper 2019/035

Using TopGear in Overdrive: A more efficient ZKPoK for SPDZ

Carsten Baum, Daniele Cozzo, and Nigel P. Smart

Abstract

The HighGear protocol (Eurocrypt 2018) is the fastest currently known approach to preprocessing for the SPDZ Multi-Party Computation scheme. Its backbone is formed by an Ideal Lattice-based Somewhat Homomorphic Encryption Scheme and accompanying Zero-Knowledge proofs. Unfortunately, due to certain characteristics of HighGear such current implementations use far too low security parameters in a number of places. This is mainly due to memory and bandwidth consumption constraints. In this work we present a new approach to the ZKPoKs as introduced in the HighGear work. We rigorously formalize their approach and show how to improve upon it using a different proof strategy. This allows us to increase the security of the underlying protocols, all while maintaining roughly the same performance in terms of memory and bandwidth consumption.

Note: Minor correction

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Published elsewhere. MINOR revision.To appear SAC 2019
Keywords
SPDZHighGearZKPoK
Contact author(s)
nigel smart @ kuleuven be
daniele cozzo @ kuleuven be
carsten baum @ biu ac il
History
2020-03-19: last of 4 revisions
2019-01-17: received
See all versions
Short URL
https://ia.cr/2019/035
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2019/035,
      author = {Carsten Baum and Daniele Cozzo and Nigel P.  Smart},
      title = {Using TopGear in Overdrive: A more efficient ZKPoK for SPDZ},
      howpublished = {Cryptology ePrint Archive, Paper 2019/035},
      year = {2019},
      note = {\url{https://eprint.iacr.org/2019/035}},
      url = {https://eprint.iacr.org/2019/035}
}
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