An Enhanced ID-Based Deniable Authentication Protocol on Pairings

Deniability is defined as a privacy property which enables protocol principals to deny their involvement after they had taken part in a particular protocol run. Lately, Chou et al. had proposed their ID-based deniable authentication protocol after proving the vulnerability to Key-Compromise Impersonation (KCI) attack in Cao et al.’s protocol. In addition, they claimed that their protocol is not only secure, but also able to achieve both authenticity and deniability properties. However, in this paper, we demonstrate that Chou et al. protocol is not flawless as it remains insecure due to its susceptibility to the KCI attack. Based on this, we propose an enhanced scheme which will in fact preserves the authenticity, the deniability and the resistance against the KCI attack.