An application on a mobile terminal in a mobile network is registered with an application server. The mobile terminal includes an identity module. At the application server, a first message is received for registering the application, the first message including a telephone number associated with the identity module. The application server generates a unique identifier and associates the unique identifier with the telephone number. A second message is sent from the application server to the mobile terminal, the second message including the unique identifier. The mobile terminal generates and stores a data block including the unique identifier, a subscriber identity associated with the identity module and a terminal identifier associated with the mobile terminal.