The new randomness beacon format standard: An exercise in limiting the power of a trusted third party

Abstract

We discuss the development of a new format for beacons–servers which provide a sequence of digitally signed and hash-chained public random numbers on a fixed schedule. Users of beacons rely on the trustworthiness of the beacon operators. We consider several possible attacks on the users by the beacon operators, and discuss defenses against those attacks that have been incorporated into the new beacon format. We then analyze and quantify the effectiveness of those defenses.