Distributed parameter generation for bilinear diffie hellman exponentiation and applications

Abstract

Distributed parameter and key generation plays a fundamental role in cryptographic applications and is motivated by the need to relax the trust assumption on a single authority that is responsible for producing the necessary keys for cryptographic algorithms to operate. There are many well-studied distributed key generation protocols for the discrete logarithm problem. In this paper, building upon previous distributed key generation protocols for discrete logarithms, we provide two new building blocks that one can use them in a sequential fashion to derive distributed parameter generation protocols for a class of problems in the bilinear groups setting, most notably the n-Bilinear Diffie Hellman Exponentiation problem. Based on this we present new applications in distributed multi-party oriented cryptographic schemes including decentralized broadcast encryption, revocation systems and identity based encryption.