Strongly secure identity-based authenticated key agreement protocols without bilinear pairings

In this paper, we present two strongly secure pairing-free identity-based (ID-based) two-party authenticated key agreement (AKA) protocols achieving implicit authentication, which are proven secure in the extended Canetti-Krawczyk (eCK) model. The proposals can offer provable security against both passive and active adversaries in the random oracle model. Our schemes capture all basic desirable security properties including key-compromise impersonation resilience, ephemeral secrets reveal resistance, (weak) perfect forward secrecy and master key forward secrecy etc. We show the security of one of these proposals can be reduced to the standard computational Diffie-Hellman assumption, and the security of the other relies on the gap Diffie-Hellman assumption while having a lower computational overhead. Currently, there are few pairing-free ID-based AKA protocols that are provably secure in such strong security models as the eCK model. Our schemes can provide strong security assurances and in the meanwhile achieve a good computational efficiency. Compared with previous related schemes, our protocols have advantages over them in security, efficiency or both.