This book constitutes the refereed proceedings of the 4th International Conference on Trust Management, iTrust 2006. 30 revised full papers and 4 revised short papers are presented together with 1 keynote paper and 7 trust management tool and systems demonstration reports. Besides technical issues in distributed computing and open systems, topics from law, social sciences, business, and philosophy are addressed.

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.