Making the Diffie-Hellman Protocol Identity-Based

Kohei Nakagawa, Atsushi Fujioka, 彰 永井 +3 more

Berkant Ustaoğlu

Hai Huang

SUMMARY This paper investigates authenticated key exchange (AKE) protocol under computational Diffie–Hellman assumption in the extended Canetti–Krawczyk model. The core technical component of our protocol is the trapdoor test technique, which is originally introduced to remove the gap Diffie–Hellman (GDH) assumption for the public key encryption schemes. Our contributions are twofold.First, we clarify some misunderstandings of the usage of the trapdoor test technique in AKE protocols showing its adaptation to the AKE protocols is not trivial. We point out some errors in some recent work which attempts to make use of the trapdoor test technique to remove GDH assumption.Second, based on trapdoor test technique, we propose an efficient extended Canetti–Krawczyk secure AKE protocol under computational Diffie–Hellman assumption instead of GDH assumption. Additionally, our protocol does not make use of NAXOS trick and has a tight reduction. In comparison with all existing AKE protocols with the properties as previously mentioned, our protocol with only three exponentiations is most efficient. Copyright © 2013 John Wiley & Sons, Ltd.

Dennis Hofheinz, Christian Matt, Ueli M. Maurer

Yuh‐Min Tseng, Tsu‐Yang Wu

In 2008, based on the two-party Diffie–Hellman technique, Biswas proposed a contributory group key exchange protocol called the Group-DH protocol. This contributory property is an important one of group key agreement. Unfortunately, in this paper we show that the proposed Group-DH protocol is not a contributory group key exchange protocol. Therefore, we propose an improved group key exchange protocol with verifiably contributory property based on the same Diffie–Hellman technique. When an identical group key is constructed, each participant can confirm that his/her contribution is actually included in the group key. We show that the improved protocol is provably secure against passive attacks under the decisional Diffie–Hellman assumption. As compared to the previously proposed group key exchange protocols, our protocol provides contributiveness and the required computational cost is suitable for low-power participants in a network environment.

Durbadal Chattaraj, Monalisa Sarma, Debasis Samanta

For a secure communication over an insecure channel the Diffie-Hellman key exchange protocol (DHKEP) is treated as the de facto standard. However, it suffers form server-side compromisation, identity compromisation, man-in-the-middle, replay attacks, etc. Also, there are single point of vulnerability (SOV), single point of failure (SOF) and user privacy preservation issues. This work proposes an identity-based two-server DHKEP to address the aforesaid issues and alleviating the attacks. To preserve user identity from outside intruders, a k-anonymity based identity hiding principle has been adopted. Further, to ensure efficient utilization of channel bandwidth, the proposed scheme employs elliptic curve cryptography. The security analysis substantiate that our scheme is provably secure and successfully addressed the above-mentioned issues. The performance study contemplates that the overhead of the protocol is reasonable and comparable with other schemes.