Paper 2022/436

Publicly Accountable Robust Multi-Party Computation

Marc Rivinius, Pascal Reisert, Daniel Rausch, and Ralf Küsters

Abstract

In recent years, lattice-based secure multi-party computation (MPC) has seen a rise in popularity and is used more and more in large scale applications like privacy-preserving cloud computing, electronic voting, or auctions. Many of these applications come with the following high security requirements: a computation result should be publicly verifiable, with everyone being able to identify a malicious party and hold it accountable, and a malicious party should not be able to corrupt the computation, force a protocol restart, or block honest parties or an honest third-party (client) that provided private inputs from receiving a correct result. The protocol should guarantee verifiability and accountability even if all protocol parties are malicious. While some protocols address one or two of these often essential security features, we present the first publicly verifiable and accountable, and (up to a threshold) robust SPDZ-like MPC protocol without restart. We propose protocols for accountable and robust online, offline, and setup computations. We adapt and partly extend the lattice-based commitment scheme by Baum et al. (SCN 2018) as well as other primitives like ZKPs. For the underlying commitment scheme and the underlying BGV encryption scheme we determine ideal parameters. We give a performance evaluation of our protocols and compare them to state-of-the-art protocols both with and without our target security features: public accountability, public verifiability and robustness.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Published elsewhere. MAJOR revision.To appear in the IEEE Symposium on Security & Privacy, May 2022
Keywords
MPCSPDZpublic accountabilitypublicly identifiable abortpublic verifiabilityrobustness
Contact author(s)
marc rivinius @ sec uni-stuttgart de
History
2022-04-07: revised
2022-04-06: received
See all versions
Short URL
https://ia.cr/2022/436
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2022/436,
      author = {Marc Rivinius and Pascal Reisert and Daniel Rausch and Ralf Küsters},
      title = {Publicly Accountable Robust Multi-Party Computation},
      howpublished = {Cryptology ePrint Archive, Paper 2022/436},
      year = {2022},
      note = {\url{https://eprint.iacr.org/2022/436}},
      url = {https://eprint.iacr.org/2022/436}
}
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