Authenticated group key agreement protocol without pairing

Abstract

Since the inception of pairing-based constructions in cryptography, the authentication in group key agreement (GKA) protocol has been usually achieved by pairings. But due to high computation cost of pairing such constructions are inefficient for practical implementation, specially for low power devices. Also, in almost all such constructions leakage of both the keys- the long-term secret key and the ephemeral key has not been considered for security guarantee. In this view, construction of an efficient and secure GKA protocol is desired. In this paper, we propose an authenticated GKA protocol without pairing. We have achieved security of the proposed scheme following the most standard and recent security notion namely the EGBG model. In particular, we have proved the authenticated key exchange (AKE) security and the mutual authentication (MA) security with full forward secrecy, considering leakage of both the keys long-term and ephemeral, adopting a comparatively efficient technique, the game hopping technique. Our proposed scheme is more efficient in the view of computation and operation time with compare to the existing similar schemes, hence it is more acceptable for the tiny processors. To the best of our knowledge ours is the first pairing free balanced AGKA protocol secure in the EGBG model.