6th Workshop on Privacy Enhancing Technologies -- Privacy for Public Transportation -- Ignoring the Great Firewall of China -- Imagined Communities: Awareness, Information Sharing, and Privacy on the Facebook -- Enhancing Consumer Privacy in the Liberty Alliance Identity Federation and Web Services Frameworks -- Traceable and Automatic Compliance of Privacy Policies in Federated Digital Identity Management -- Privacy Injector — Automated Privacy Enforcement Through Aspects -- A Systemic Approach to Automate Privacy Policy Enforcement in Enterprises -- One Big File Is Not Enough: A Critical Evaluation of the Dominant Free-Space Sanitization Technique -- Protecting Privacy with the MPEG-21 IPMP Framework -- Personal Rights Management – Taming Camera-Phones for Individual Privacy Enforcement -- Improving Sender Anonymity in a Structured Overlay with Imprecise Routing -- Selectively Traceable Anonymity -- Valet Services: Improving Hidden Servers with a Personal Touch -- Blending Different Latency Traffic with Alpha-mixing -- Private Resource Pairing -- Honest-Verifier Private Disjointness Testing Without Random Oracles -- A Flexible Framework for Secret Handshakes -- On the Security of the Tor Authentication Protocol -- Optimal Key-Trees for Tree-Based Private Authentication -- Simple and Flexible Revocation Checking with Privacy -- Breaking the Collusion Detection Mechanism of MorphMix -- Linking Anonymous Transactions: The Consistent View Attack -- Preserving User Location Privacy in Mobile Data Management Infrastructures -- The Effects of Location Access Behavior on Re-identification Risk in a Distributed Environment.

This book constitutes the thoroughly refereed post-proceedings of the 6th International Workshop on Privacy Enhancing Technologies, PET 2006, held in Cambridge, UK, in June 2006 co-located with WEIS 2006, the Workshop on the Economics of Information Security, and WOTE 2006, the IAVoSS Workshop On Trustworthy Elections. The 24 revised full papers presented were carefully selected from 91 submissions during two rounds of reviewing and improvement. The papers both from academia and industry present novel research on all theoretical and practical aspects of privacy technologies, as well as experimental studies of fielded systems.