Round-optimal deniable ring authentication in the presence of big brother

Abstract

In this work we propose a Deniable Ring Authentication scheme secure against a powerful Big Brother type of adversary and yielding an optimal number of communication rounds. Our scheme is based on an infra-structure assumption: the existence of verifiable Broadcast Encryption. Particularly, our solution can be instantiated by using the Broadcast Encryption protocol of Boneh, Gentry and Waters (CRYPTO 2005), resulting in a Deniable Ring Authentication protocol with constant message size. © 2011 Springer-Verlag.