Paper 2022/1759

Bingo: Adaptively Secure Packed Asynchronous Verifiable Secret Sharing and Asynchronous Distributed Key Generation

Abstract

In this work we present Bingo, an adaptively secure and optimally resilient packed asynchronous verifiable secret sharing (PAVSS) protocol that allows a dealer to share $f+1$ secrets or one high threshold secret with a total communication complexity of just $O(\lambda n^2)$ words. Bingo requires a public key infrastructure and a powers-of-tau setup. Using Bingo's packed secret sharing, we obtain an adaptively secure validated asynchronous Byzantine agreement (VABA) protocol that uses $O(\lambda n^3)$ expected words and constant expected time. Using this agreement protocol in combination with Bingo, we obtain an adaptively secure high threshold asynchronous distributed key generation (ADKG) of standard field element secrets that uses $O(\lambda n^3)$ expected words and constant expected time. To the best of our knowledge, Bingo is the first ADKG to have an adaptive security proof and have the same asymptotic complexity of the best known ADKG's that only have non-adaptive security proofs.