  Buoyed by the excitement around secure decentralized applications, the last
few decades have seen numerous constructions of distributed randomness beacons
(DRB) along with use cases; however, a secure DRB (in many variations) remains
an open problem. We further note that it is natural to want some kind of reward
for participants who spend time and energy evaluating the randomness beacon
value -- this is already common in distributed protocols.
  In this work, we present RandGener, a novel $n$-party commit-reveal-recover
(or collaborative) DRB protocol with a novel reward and penalty mechanism along
with a set of realistic guarantees. We design our protocol using trapdoor
watermarkable verifiable delay functions in the RSA group setting (without
requiring a trusted dealer or distributed key generation).

Cryptography and Security