Method for a delegated authentication of broadcasting services based on mobile multicast techniques over internet environment

A method for a delegated authentication of broadcasting services based on mobile multicast techniques over internet environment is provided to perform the delegated authentication through a secure relay server whenever a mobile terminal is moved to a new network. A method for a delegated authentication of broadcasting services based on mobile multicast techniques over internet environment comprises four steps. In a first step, A hand-off of a mobile terminal subscribed to a first secure relay server is generated. The first secure relay server requests the delegated authentication of the mobile terminal to a second secure relay server(S210,S215,S220). In a second step, the second secure relay server determines whether the authentication is possible or not(S225). In a third step, the second secure relay server transmits a multicast broadcasting data and constructs an IP address of the mobile terminal(S230,S235). In a fourth step, the first and second secure relay servers perform the subscription and withdrawal of the mobile terminal for a multicast group. The second secure relay server transmits the multicast broadcasting data authenticated with its own group key to the mobile terminal(S240,S245).