Paper 2019/1182

Robust Secret Sharing with Optimal Share Size and Security Against Rushing Adversaries

Serge Fehr and Chen Yuan

Abstract

We show the first robust secret sharing scheme for a maximal threshold $t < n/2$ that features an optimal overhead in share size, offers security against a rushing adversary, and runs in polynomial time. Previous robust secret sharing schemes for $t < n/2$ either suffered from a suboptimal overhead, offered no (provable) security against a rushing adversary, or ran in superpolynomial time.