Abstract: A method for issuing an electronic identity based on previously certified electronic identity. This is accomplished by providing a method to use a previously certified identity to create another representational form for the same identity. This way the holder of a certificate can extend his or her already verified identity for other uses. The previously certified identity can be for instance so called mobile identity which is associated to a person's mobile terminal such as mobile phone. The person can show to certificate be his/her own by using the digital signature feature of the mobile terminal.

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.