Discovering Services Is Not Enough

Abstract

In the future, mobile users will find themselves in unfamiliar and "chaotic" environments with multiple providers of electronic devices or services, and competing internetservice providers. Users need to discover what services are available, how to apply them to the task at hand, and how to acquire the appropriate rights to use them successfully. The key contribution of this paper is linking service discovery with the acquisition of role-based credentials for services, and showing how the combination can be exploited easily and effectively by users of ubiquitous-computing environments. Our design facilitates flexible authorisation and access control, requires no special-purpose client devices or software, and enables an open market where all participants have a niche that they perceive as bringing value to them. The design has been refined, implemented, and validated as part of a larger prototype implementation, parts of which are described. Middleware, running in a web proxy, transforms web objects by adding specific software tools for the user to discover and invoke the currently relevant services.