Robust smart card secured authentication scheme on SIP using Elliptic Curve Cryptography

In 2014, Yeh et al. proposed a robust smart card secured authentication scheme on SIP using elliptic curve cryptography to conquer many forms of attacks in previous protocols. Yeh et al. claimed that their proposed protocol is more efficient than Diffie-Hellman’s concept authentication protocols for SIP and performs secured mutual authentication, which can be implemented on different real network environments such as VoIP. However, this paper points out that Yeh et al.’s protocol not only suffers from stolen smart card attack, but also does not provide perfect forward secrecy.