Broadcast-Optimal Two Round MPC with Asynchronous Peer-to-Peer Channels

Ivan Damgård, Divya Ravi*, Luisa Siniscalchi, Sophia Yakoubov

*Corresponding author for this work

Research output: Contribution to book/anthology/report/proceedingArticle in proceedingsResearchpeer-review

Abstract

In this paper we continue the study of two-round broadcast-optimal MPC, where broadcast is used in one of the two rounds, but not in both. We consider the realistic scenario where the round that does not use broadcast is asynchronous. Since a first asynchronous round (even when followed by a round of broadcast) does not admit any secure computation, we introduce a new notion of asynchrony which we call -asynchrony. In this new notion of asynchrony, an adversary can delay or drop up to of a given party’s incoming messages; we refer to as the deafness threshold. Similarly, the adversary can delay or drop up to of a given party’s outgoing messages; we refer to as the muteness threshold. We determine which notions of secure two-round computation are achievable when the first round is -asynchronous, and the second round is over broadcast. Similarly, we determine which notions of secure two-round computation are achievable when the first round is over broadcast, and the second round is (fully) asynchronous. We consider the cases where a PKI is available, when only a CRS is available but private communication in the first round is possible, and the case when only a CRS is available and no private communication is possible before the parties have had a chance to exchange public keys.

Original languageEnglish
Title of host publicationProgress in Cryptology – LATINCRYPT 2023 : 8th International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2023, Quito, Ecuador, October 3–6, 2023, Proceedings
EditorsAbdelrahaman Aly, Mehdi Tibouchi
Number of pages20
Place of publicationCham
PublisherSpringer
Publication dateSept 2023
Pages87-106
ISBN (Print)978-3-031-44468-5
ISBN (Electronic)978-3-031-44469-2
DOIs
Publication statusPublished - Sept 2023
Event8th International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2023 - Quito, Ecuador
Duration: 3 Oct 20236 Oct 2023

Conference

Conference8th International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2023
Country/TerritoryEcuador
CityQuito
Period03/10/202306/10/2023
SeriesLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume14168
ISSN0302-9743

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