Managing Evolving Trust Policies within Open and Decentralized Communities

International audienceOnline communities promise a new era of flexible and dynamic collaborations. However, these features also raise new security challenges, especially regarding how trust is managed. In this paper, we focus on situations wherein communities participants collaborate with each others via software agents that take trust decisions on their behalf based on policies. Due to the open and dynamic nature of Online Communities, participants can neither anticipate all possible interactions nor have foreknowledge of sensitive resources and potentially malicious partners. This makes the specification of trust policies complex and risky, especially for collective (i.e., community-level) policies, motivating the need for policies evolution. The aim of this paper is to introduce an approach in order to manage the evolution of trust policies within online communities. Our scenario allows any member of the community to trigger the evolution of the community-level policy and make the other members of the community converge towards it