Expose or not? A progressive exposure approach for service discovery in pervasive computing environments

In pervasive computing environments, service discovery facilitates users to access network services by automating tedious manual configurations. When network services become pervasive, the number of service providers also increase dramatically. Because of security and privacy concerns, network services are segmented by service providers. Existing service discovery protocols, however, do not address how to facilitate users to properly identify and authenticate with existing service providers. Without prudence, sensitive information may be exposed. Conversely, with prudence both users and service providers prefer the other party to expose sensitive information first. We identify that even among legitimate users and service providers, there are privacy concerns that may be expressed as a chicken-and-egg problem. In this paper, we propose a progressive approach to solve the problem. Users and service providers expose minimal sensitive information in turn and identify necessary exposure during the process. Theoretical analysis, simulation, and experiments show that our approach protects sensitive information with little overhead.