Invited Talks -- Why We Need a Non-reductionist Approach to Trust -- Full Papers -- Dynamic Trust Federation in Grids -- Being Trusted in a Social Network: Trust as Relational Capital -- A Requirements-Driven Trust Framework for Secure Interoperation in Open Environments -- Normative Structures in Trust Management -- Gathering Experience in Trust-Based Interactions -- Multilateral Decisions for Collaborative Defense Against Unsolicited Bulk E-mail -- Generating Predictive Movie Recommendations from Trust in Social Networks -- Temporal Logic-Based Specification and Verification of Trust Models -- Modelling Trade and Trust Across Cultures -- Estimating the Relative Trustworthiness of Information Sources in Security Solution Evaluation -- Trust-Based Route Selection in Dynamic Source Routing -- Implementing Credential Networks -- Exploring Different Types of Trust Propagation -- PathTrust: A Trust-Based Reputation Service for Virtual Organization Formation -- A Versatile Approach to Combining Trust Values for Making Binary Decisions -- Jiminy: A Scalable Incentive-Based Architecture for Improving Rating Quality -- Virtual Fingerprinting as a Foundation for Reputation in Open Systems -- Towards Automated Evaluation of Trust Constraints -- Provision of Trusted Identity Management Using Trust Credentials -- Acceptance of Voting Technology: Between Confidence and Trust -- B-Trust: Bayesian Trust Framework for Pervasive Computing -- TATA: Towards Anonymous Trusted Authentication -- The Design, Generation, and Utilisation of a Semantically Rich Personalised Model of Trust -- A Trust Assignment Model Based on Alternate Actions Payoff -- Privacy, Reputation, and Trust: Some Implications for Data Protection -- A Reputation-Based System for Confidentiality Modeling in Peer-to-Peer Networks -- Robust Reputationsfor Peer-to-Peer Marketplaces -- From Theory to Practice: Forgiveness as a Mechanism to Repair Conflicts in CMC -- A Novel Protocol for Communicating Reputation in P2P Networks -- A Scalable Probabilistic Approach to Trust Evaluation -- Demonstration Overviews -- The Agent Reputation and Trust (ART) Testbed -- Trust Establishment in Emergency Case -- Evaluating Trust and Authenticity with Caution -- Using Jiminy for Run-Time User Classification Based on Rating Behaviour -- Traust: A Trust Negotiation Based Authorization Service -- The Interactive Cooperation Tournament -- eTVRA, a Threat, Vulnerability and Risk Assessment Tool for eEurope.

This volume constitutes the proceedings of the 4th International Conference on Trust Management, held in Pisa, Italy during 16-19 May 2006. The conference followed successful International Conferences in Crete in 2003, Oxford in 2004 and Paris in 2005. The ?rst three conferences were organized by iTrust, which was a working group funded as a thematic network by the Future and Emerging Technologies(FET) unit of the Information Society Technologies(IST) program of the European Union. The purpose of the iTrust working group was to provide a forum for cro- disciplinary investigation of the applications of trust as a means of increasing security, building con?dence and facilitating collaboration in dynamic open s- tems. The aim of the iTrust conference series is to provide a common forum, bringing together researchers from di?erent academic branches, such as the technology-oriented disciplines, law, social sciences and philosophy, in order to develop a deeper and more fundamental understanding of the issues and ch- lenges in the area of trust management in dynamic open systems. The response to this conference was excellent; from the 88 papers submitted to the conference, we selected 30 full papers for presentation. The program also included one keynote address, given by Cristiano Castelfranchi; an industrial panel; 7 technology demonstrations; and a full day of tutorials.