Group key agreement from bilinear pairings

Abstract

The use of bilinear pairings as a building block for cryptographic protocols, most notably in the construction of identity-based cryptosystems, is a very popular area of cryptographic research. In this thesis, we provide a novel classification of pairing-based group key agreement (GKA) from current literature. We propose a new framework for constructing secure and efficient computationally asymmetric authenticated GKA protocols from identity-based signcryption schemes and adapt this framework to construct a novel identity-based authenticated GKA protocol with perfect forward secrecy. To the best of our knowledge, our protocol is the first that maintains perfect forward secrecy in the presence of auxiliary key agreement protocols. We formally prove the security of our protocols in the random oracle model and show that they are communication and computationally efficient in comparison to the pairing-based protocols from the literature.