This book constitutes the refereed proceedings of the Third International Conference on Trust and Privacy in Digital Business, TrustBus 2006, held in Krakow, Poland in September 2006 in conjunction with DEXA 2006.The 24 revised full papers presented were carefully reviewed and selected from 70 submissions. The papers are organized in topical sections on privacy and identity management, security and risk management, security requirements and development, privacy enhancing technologies and privacy management, access control models, trust and reputation, security protocols, and security and privacy in mobile environments.