Abstract: A method and system for identifying digitally signed messages in a telecommunication system that includes a telecommunication network, a mobile station connected to the telecommunication network and which has an associated subscriber identity module, a network server connected to the telecommunication network, and a database connected to the network server and which stores a list of identification numbers for each mobile station. When a message is to be sent from, for example, a mobile station to the network server, a first authentication unit in the mobile station attaches to the message a message identification number that has been increased or incremented from the number attached to a previous message sent from the mobile station.

Abstract: The present invention provides, for use in telecommunication systems, a system and method enabling implementation of dynamic memory management in a subscriber identity module via an application or management system stored in the subscriber identity module. The memory regions in the subscriber identity module can be dynamically allocated to store or accommodate customers' and service providers' own applications, and the amount of information that the system operator need to store relating to the memory structures of and stored applications in subscriber identity modules that it owns or controls is significantly reduced.

Abstract: Payment using a payment card for goods and/or services ordered online via an information network such as the Internet is implemented in a notably secure manner without the need to transmit the client's payment card number over the data transmission network. A separate confirmation for effecting the payment for an order is requested from the client. The information to be confirmed is transmitted to the terminal device of the client, such as a mobile station, by means of which the client confirms the order by digitally signing the confirmation request. The digitally signed confirmation and the electronic identity information associated with the client are then returned to the payment service equipment, which verifies the client's identity, checks the validity of the client's payment card, and then transmits the necessary payment information to the payment system.