Trust negotiations for collaborative environments: Principles, concepts and systems

This tutorial will present an overview of the trust negotiation paradigm, an innovative authorization approach that has been widely investigated in the recent years. We will present the basic concepts related to trust negotiation, and provide an overview of the different approaches proposed to conduct negotiations. We will focus on trust negotiation research advances, that is, how the trust negotiation paradigm has changed and improved since it was first proposed and how it has been integrated with other research areas. In particular, we will present trust negotiations recent improvements with respect to privacy preserving technologies and cryptographic techniques. Both theoretical aspects and architectural aspects of trust negotiations will be discussed. We will analyze and thoroughly compare existing work and study the various advantages/disadvantages of each proposal. Examples of trust negotiations projects that will be discussed include PeerTrust, Trust-X, Unipro, RT, Traust and others. As a representative example, we will illustrate the research project conducted at Purdue University and University of Milan, referred to as Trust-X. We will discuss the unique features of Trust-X and show the approaches supported by Trust-X to carry on trust negotiations. We will also present the recently added features to guarantee anonymous Trust Negotiations. Interesting architectural aspects of Trust-X will also be discussed along with the key implementation features. Performance and evaluations will be conducted. We will briefly discuss also on-going project, such as the migration of Trust-X in peer-to-peer platform and the required extensions to achieve advanced trust negotiations in peer-to-peer systems. To help the attendees´ understanding and intuition, we will use several examples and discuss potential application domains. To this extent, we will show demos of Trust-X functioning and of other existing trust negotiation systems.