An identity based service system is provided, in which an identity is created and managed for a user or principal, such that at least a portion of the identity is available to use between one or more system entities. A discovery service enables a system entity to discover a service descriptor, given a service name and a name identifier of the user, whereby system entities can find and invoke the user's other personal web services. The discovery service preferably provides a translation between a plurality of namespaces, to prevent linkable identity information over time between system entities.