TMQV: A Strongly eCK-secure Diffie-Hellman Protocol without Gap Assumption

 

Jiaxin Pan and Libin Wang

 

School of Computer, South China Normal University

Guangzhou 510631, China

csplator@gmail.com, lbwang@scnu.edu.cn

 

Abstract

In this paper, we propose an authenticated key exchange (AKE) protocol under the computational

Diffie-Hellman (CDH) assumption with respect to the strengthened eCK-security (seCK-security) of

Sarr et al.. To date, many AKE protocols either are provably secure under a rather strong and nonstandard

assumption named as the gap Diffie-Hellman (GDH) assumption, or fall to practical attacks

on the intermediate result leakage which can be captured by the seCK model. In order to remove

the gap assumption and to achieve stronger security requirements, we present the TMQV protocol

using the twinning technique and the MQV key derivation method. With the help of trapdoor test

theorem, TMQV is provably seCK-secure under the standard CDH assumption in the random oracle

model. Compared with the related works, TMQV achieves not only stronger security but also higher

implementation efficiency with weaker cryptographic assumptions.

 

Keywords: Strengthened eCK model, authenticated key exchange, Diffie-Hellman assumption, trapdoor test

 

Journal of Internet Services and Information Security (JISIS), 1(2/3): 107-124, August 2011 [pdf]