An eCK-Secure One Round Authenticated Key Exchange Protocol

with Perfect Forward Security

Hai Huang

Zhejiang Sci-Tech University

Hangzhou, 310000 P.R. China

haihuang1005@gamil.com

Abstract

This paper investigates the two-pass (one round) authenticated key exchange protocol in the enhanced

Canetti-Krawczyk (eCK) model with perfect forward security against active adversary. Currently,

there exist no authenticated key exchange protocols which are provably secure in the eCK

model and meanwhile achieve perfect forward security against active adversary in one round.

We propose a new two-pass (one round) authenticated key exchange protocol which enjoys following

desirable properties. First, our protocol is shown secure in the eCK model under the gap

Diffie-Hellman (GDH) assumption. Moreover, our protocol does not use the NAXOS transformation,

the drawback of which will be discussed in the introduction. Second, under the same assumption,

we prove that our protocol achieves perfect forward security against active adversary in one round.

To the best of our knowledge, our proposal is the first two-pass (one round) authenticated key

exchange protocol provably secure in the eCK model and achieving perfect forward security against

active adversary.

Keywords: Authenticated key exchange, eCK model, Perfect forward security, Provably secure