In this work, we present the first efficient MPC protocols with identifiable abort in the dishonest majority setting, which run in a constant number of rounds and make only black-box use of cryptographic primitives. Our main construction is built from highly efficient primitives in a careful way to achieve identifiability at a low cost. In particular, we avoid the use of public-key operations outside of a setup phase, incurring a relatively low overhead on top of the fastest currently known constant-round MPC protocols based on garbled circuits. Our construction also avoids the use of adaptively secure primitives and heavy zero-knowledge machinery, which was inherent in previous works. In addition, we show how to upgrade our protocol to achieve public verifiability using a public bulletin board, allowing any external party to verify correctness of the computation or identify a cheating party.
Category / Keywords: cryptographic protocols / Secure Multiparty Computation, Identifiable Abort, Constant Round Original Publication (with minor differences): IACR-CRYPTO-2020 Date: received 22 Jun 2020 Contact author: carsten baum at outlook com, eduardo at cs au dk Available format(s): PDF | BibTeX Citation Version: 20200624:075145 (All versions of this report) Short URL: ia.cr/2020/767