SPoX: combining reactive Semantic Web policies and Social Semantic Data to control the behaviour of Skype

In this demo paper we describe SPoX, a tool that allows to define the behaviour of Skype based on reactive Semantic Web policies. SPoX (Skype Policy Extension) enables users to define policies stating, for example, who is allowed to call and whose chat messages show up. Moreover, SPoX reacts to arbitrary events in Skype's Social Network as well, such as on-line status changes of users or the birthday of a friend. The decisions about how SPoX reacts are defined by means of Semantic Web policies that do not only consider the context of the user (such as time or on-line status) but include Social Semantic Web data into the policy reasoning process. By this means, users can state that, for instance, only people defined as friends in their FOAF profile, only friends on Twitter, or even only people they wrote a paper with are allowed to call. Further, SPoX exploits Semantic Web techniques for advanced negotiations by means of exchanging policies over the Skype application channel. This procedure allows two clients to negotiate trust based on their SPoX policies before a connection - for example a Skype call - is established.
Published in 2009