An Efficient Multiple PKG Compatible Identity Based Authenticated Key Agreement protocol

Abstract

In this paper we propose an efficient single-round, two-party identity based authenticated key agreement protocol in the setting of multiple Private Key Generators (PKGs). One of the major advantages of our construction is that it does not involve any pairing operations. To date, existing protocols in the Identity Based Key Agreement domain revolves around a single PKG environment. Efforts to exploit the multiple PKGs paradigm have placed excessive reliance on Elliptic Curve Cryptography and bilinear pairings. These are computationally intensive and cannot be used when computation is premium, specially in applications such as in a Vehicular Ad-Hoc Network (VANET) where the vehicles in a VANET may need to perform a large number of key agreement sessions. Previous attempts to model identity based key agreement in multiple PKG scenario by Chen and Kundla, McCullagh have very limited scope and provide weak security guarantees. We propose a new security model for identity based key agreement protocols involving multiple PKGs based on the eCK security model which is much more stronger than the existing models and captures additional properties like Key Compromise Impersonation and forward secrecy that were not captured by the previous models. Our protocol is proven secure in this new security model under the Gap Diffie Hellman (GDH) assumption in the Random Oracle (RO) model