For many years, the pay-TV system has attracted a lot of users. Users have recently expressed the desire to use mobile TV or mobile payment via anonymous protocols. The mobile users have also received their services over cellular communications networks. Each mobile device receives services from each head end systems. With increasing numbers of users and the expansion of Internet, user’s privacy has become crucial important. When a device leaves the head end system’s range, it must receive services from another head end system. In this paper, we review ’s scheme and we highlight some weaknesses, including privilege insider attack and user traceability attack. Finally, we alleviate the scheme and analyze the alleviated scheme using both heuristic and formal methods.
With the integration of wireless communication and pay-TV, mobile broadcast TV technologies have advanced noticeably in recent years. In 2011, proposed an efficient anonymous authentication protocol for mobile pay-TV and claimed that their protocol is secure and efficient. However, Kim showed that their protocol has weaknesses in password guessing attack and impersonation attack with the assumption that attacker could get user’s smart card. Thereby, this paper proposes an anonymous authentication protocol to solve the flaws in ’s protocol. In terms of convenience requirements, mobility has been one of the most important services for pay-TV systems. In 2009, Yang and Chang proposed an authentication protocol for mobile devices using elliptic curves cryptography (ECC) and claimed that their mechanism is secure and efficient using in mobile pay-TV systems. In this paper, we demonstrate that their protocol still is insecure for authentication without password protection and performs inefficiently. Therefore, we offer an anonymous authentication protocol (AAP) to solve the performance issue and insecure risks. In addition, we present an analysis of our protocol to show that our protocol suits better for applications with higher security requirements and low power-consuming devices. Recently, Sun and Leu proposed an efficient authentication scheme for access control in mobile pay-TV systems based on pairing and elliptic curve cryptography. In Sun and Leu's scheme, there exist two fatal security flaws, including 1) failure in subscriber authentication and 2) vulnerable to unauthorized access, which contradict to the security claims of Sun and Leu's scheme. To meet the claimed security requirements, we strengthen Sun and Leu's scheme with only lightweight modifications. 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.