Recently, IPTV brings a lot of attraction because it is different from the traditional TV system in that it can provide the contents any time on users' demand. Many industries are starting new services based on IPTV expecting great growth of the market. From the static IPTV service, newer IPTV related service is considering openness. In Open IPTV, any user can send or receive the contents from another user, which means the customer can be the service provider at the same time. On top of the openness, mobility is another important concept to be considered in the IPTV industry. With the mobility and the openness, IPTV service has newer technical and security issues for reliable services. In this work, we propose a mutual authentication mechanism required between content provider and receiver. For communication, two users need to authenticate each other. Because of the openness and the mobility, the mechanism should be lightweight and dynamic. We have adopted Visual Cryptography and Steganography concept for efficient and lightweight authentication.