Patent ID: 6993666

Claim:
In a data communication system in which a remote user of a service provided by a server on a network of the system is required to transmit to the server a valid expendable password, from a set of expendable passwords provided to the user, in order to obtain remote user-access to the service via the network, the improvement comprising a terminal device connected to the network for use by the user in remotely accessing the service via the network, said terminal device comprising: storage means for storing at the terminal device the set of expendable passwords provided to the user for use in remotely accessing the service from the terminal device via the network; selecting means for automatically selecting, from the stored set of expendable passwords at user log-on to the service, one of the stored passwords for use in remotely logging-on to the service from the terminal device; and adding means for automatically adding, to a connection setup signal to be transmitted from the terminal device to the server over the network to remotely log-on to the service from the terminal device of the user, the one of the stored passwords selected by said selecting means, wherein the network is a GSM network and said terminal device comprises a GSM mobile telephone, said terminal device further comprising a subscriber identity module that implements said selecting means and said adding means in software on said subscriber identity module, said software on the subscriber identity module further comprising means for identifying the service by a telephone number entered by the user at the terminal device to access the service, and said adding means further comprising means for appending, to the telephone number, a predetermined number of digits characterizing the one of the stored passwords selected by said selecting means.