High Throughput Secure MPC over Small Population in Hybrid Networks (Extended Abstract)

摘要

We study secure multi-party computation (MPC) among small number of parties, in partially synchronous and completely asynchronous settings. Prior works have only considered the synchronous setting. The setting considered in this paper is that of n = 4 parties with t = 1 corruption. In this setting, we present the following results. 1. A perfectly-secure protocol in the partially synchronous setting with 2 synchronous rounds. Our protocol simultaneously enjoys the properties of optimal resilience and optimal number of synchronous rounds and it partially answers one of the open problems of Patra and Ravi (IEEE Transactions on Information Theory, 2018). 2. A cryptographically-secure protocol in the partially synchronous set- ting with 1 initial synchronous round. Our protocol has optimal resilience and optimal number of synchronous rounds. The previous such protocol (Beerliova, Hirt and Nielsen, PODC 2010) requires expensive public-key machinery and associated zero-knowledge (ZK) proofs and it was left as an open problem to reduce the cryptographic setups of their protocol. Our protocol makes inroads into solving this problem, where we deploy only standard symmetric-key gadgets and completely shun ZK proofs. Our protocol also improves upon the protocol of Beerliova et al, in terms of communication complexity. 3. A cryptographically-secure protocol in the asynchronous setting, rely- ing only on symmetric-key primitives. It improves upon the previous best protocols (Choudhury et al, ICDCN 2015 and Cohen, PKC 2016), which deploy expensive public-key tools and ZK protocols.