A mobile terminal for use with a cellular or mobile telecommunications network includes a normal execution environment and a secure execution environment The mobile terminal enables the software of the terminal in the secure execution environment to be updated. The terminal may be provided with minimal software initially in the secure execution environment, and is operable to subsequently update the software by over the air transmission of software. Also disclosed is a method for managing rights in respect of broadcast, multicast and/or unicast (downloaded) data. The method defines a service protection platform implemented on mobile terminals having both normal execution environment and secure execution environment. Service protection is provided by separating the operation of service protection application components into those that operate in the normal environment and those that are adapted to execute only in the secure execution environment.