Exploiting Preferences for Minimal Credential Disclosure in Policy-Driven Trust Negotiations

Business processes in open distributed environments such as the Web force users to interact with other parties be it users or companies even if they have never had any common transaction in the past. Policy-driven trust negotiations emerged in order to address these situations. But although many policy languages and protocols have been defined, the problem of deciding which credential disclosure set to choose from those that possibly make a negotiation succeed is still subject of research. This paper explores the use of qualitative preferences in order to solve the problem and exploits the recently introduced notions of amalgamated and incremented preferences in order to allow for automated decisions which negotiations are preferred by the user. Our solution eases the task for the user of selection among all possible negotiations by removing irrelevant alternatives and it may even automatize negotiations that otherwise would require manual intervention.