Paper 2018/467

Error-Detecting in Monotone Span Programs with Application to Communication Efficient Multi-Party Computation

Nigel P. Smart and Tim Wood

Abstract

Recent improvements in the state-of-the-art of MPC for non-full-threshold access structures introduced the idea of using a collision-resistant hash functions and redundancy in the secret-sharing scheme to construct a communication-efficient MPC protocol which is computationally-secure against malicious adversaries, with abort. The prior work is based on replicated secret-sharing; in this work we extend this methodology to {\em any} multiplicative LSSS implementing a $Q_2$ access structure. To do so we need to establish a folklore property of error detection for such LSSS and their associated Monotone Span Programs. In doing so we obtain communication-efficient online and offline protocols for MPC in the pre-processing model.