Abstract: Method, system or Universal Integrated Circuit Card (UICC) for or configured to provision a UICC, with a key, the UICC containing an initial subscriber key shared between the UICC and an authentication centre, comprising: exchanging a new key between the UICC and the authentication centre using a communication between the UICC and the authentication centre authenticated using the initial subscriber key. Using the new key, in place of the initial subscriber key, for further communications with the UICC.

Abstract: A Proximity Request is handled within a cellular network, by communicating a Map Request from the Proximity Service Function to an Application Server, in response to a first Proximity Request on behalf of a first User Equipment. A Map Response is then communicated from the Application Server to the Proximity Service Function, in response to the Map Request. One or both of: the Map Request; and the Map Response comprises a cryptographic signature to allow authentication of the first Proximity Request.

Abstract: A method for controlling use of an application APPI on a mobile device, the method including determining whether a user security code is active and only allowing execution of the application if the user security code is active. The user security code may be a SIM PIN or a mobile device PIN. The user security code is non-application specific and may be required for some other purpose not related to the application, such as to allow the mobile device to authenticate with the cellular telecommunications network. In this way, the user security code entered for a different purpose may be conveniently used to automatically allow execution of an application.

Abstract: To facilitate a change in network authentication key (Ki) for use by a smart card (SIM) during authentication on a cellular telecommunications network, there is provided a smart card management scheme that combines key derivation with over the air (OTA) provisioning. This scheme ensures both that the Ki is never transmitted OTA and that the Ki is stored in two locations only: on the SIM and at an authentication centre (AuC).

Abstract: Security of communications between a mobile terminal 1 and a cellular network node (base station 3) is enhanced. A communication session transmitted on a first traffic channel ‘0’ is encrypted using a key ‘KA’. The security is enhanced by causing the communication channel to change to a second communication channel ‘7’ after a predetermined time, preferably very quickly after establishing the key. In one embodiment the communication channel then changes to a third communication channel ‘25’ after a predetermined time. In another embodiment the communication session is encrypted using a second key ‘KB’after causing the communication channel to change to the second communication channel ‘7’.