One of the promising multimedia services is the mobile pay-TV service. Due to its wireless nature, mobile pay-TV is vulnerable to attacks especially during hand-off. In 2011, an efficient anonymous authentication protocol for mobile pay-TV is proposed. The authors claim that their scheme provides an anonymous authentication to users by preventing intruders from obtaining users’ IDs during the mutual authentication between mobile subscribers and head end systems. However, after analysis, it was found that the scheme does not provide anonymous authentication and users can be easily tracked while using their anonymous identity. The scheme is also subject to denial of service attack. In this paper the deficiencies of the original scheme are demonstrated, and then a proposed improved scheme that eliminates these deficiencies is presented.
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