Patent attributes
When a mobile terminal (10), having a basic identity module (12) operative according to a first security standard, initiates a service access, the home network (30) determines whether the mobile terminal has an executable program (14) configured to interact with the basic identity module for emulating an identity module according to the second security standard. If it is concluded that the mobile terminal has such an executable program, a security algorithm is executed at the home network (30) to provide security data according to the second security standard. At least part of these security data are then transferred, transparently to a visited network (20), to the mobile terminal (10). On the mobile terminal side, the executable program (14) is executed for emulating an identity module according to the second security standard using at least part of the transferred security data as input. Preferably, the first security standard corresponds to a 2G standard, basically the GSM standard and the second security standard at least in part corresponds to a 3G standard such as the UMTS standard, and/or the IP Multimedia Sub-system (IMS) standard.