No abstract

In 2012, Xie proposed an authentication scheme based on Elliptic Curve Cryptography (ECC) for Session Initiation Protocol (SIP). However, this paper demonstrates that the Xie's scheme is vulnerable to impersonation at-tack by which an active adversary can easily forge the server's identity. Based on this attack, we also show that the Xie's scheme is also defenceless to off-line password guessing attack. Therefore, we propose a more secure and efficient scheme, which does not only cover all the security flaws and weaknesses of related previous protocols, but also provides more functionalities. We also evaluate the proposed protocol by AVISPA (Automated Validation of Internet Security Protocols and Applications) tools and confirm its security attributes.

No abstract

No abstract

To guarantee the secure access by authorized subscribers in mobile pay-TV systems, user authentication is required. User authentication is a security mechanism used to verify the identity of a legal subscriber. In 2012, Yeh and Tsaur proposed an authentication scheme for access control in mobile pay-TV systems to improve the Sun and Leu's scheme. Yeh and Tsaur claimed that their scheme meets all security requirements for mobile pay-TV systems. However, this paper indicates that Yeh and Tsaur's scheme suffers from some critical weaknesses. An attacker without knowing secret information can successfully impersonate both mobile sets and head-end system. As a remedy, we propose an improved authentication scheme for mobile pay-TV systems using bilinear pairings. The proposed scheme maintains the merits and covers the demerits of the previous schemes, and provides a higher level of the efficiency for mobile pay-TV systems.