Adaptively Secure (Aggregatable) PVSS and Application to Distributed Randomness Beacons

Publicly Verifiable Secret Sharing (PVSS) is a fundamental primitive that allows to share a secret S among n parties via a publicly verifiable transcript T. Existing (efficient) PVSS are only proven secure against static adversaries who must choose who to corrupt ahead of a protocol execution. As a result, any protocol (e.g., a distributed randomness beacon) that builds on top of such a PVSS scheme inherits this limitation. To overcome this barrier, we revisit the security of PVSS under adaptive corruptions and show that, surprisingly, many protocols from the literature already achieve it in a meaningful way: