Patent ID: 8457318

Claim:
A method to continuously transmit encrypted data of a broadcast service from service access networks having different key hierarchies to a mobile terminal, comprising: receiving, at the mobile terminal broadcast service, data of the broadcast service encrypted by a first data content encryption key, upon changing from a first service access network to a second service access network; providing the broadcast service data encrypted by a second data content encryption key, and receiving by the mobile terminal an encrypted key of the key hierarchy of the second service access network, the encrypted key being encrypted by a user-specific key of the first service access network; and sending, from the mobile terminal to the access control server of the first service access network, a changeover request message requesting a changeover from the first service access network to the second service access network, and wherein the request message includes a user identity, an identity of the access control server of the second service access network, and an identity of the broadcast service, and the changeover request message is used to enable the continuous transmission of the broadcast service via the second service access network without requiring authentication to the second service access network.