Provision of services over a common delivery platform such as a mobile telephony network

One embodiment of a system for providing services to subscribers of a network supports the provision of a plurality of different services to multiple subscribers. A processor arrangement is provided for hosting the different services. A data structure is provided for storing data associated with subscribers of the system, wherein data associated with subscribers of the system comprises a plurality of sets of data, each set of data relating to a respective level of authentication. A trust model comprises a set of relationships between the sets of data, and the trust model determines the access rights of subscribers to different services in dependence on the data set which has been used to authenticate the subscriber in a given subscriber session. The use of this trust model enables services and other access rights to be provided to a subscribed which match the level of authentication which has been applied to the subscriber during any particular session.