2010 Program Committee, Workshop on Privacy on the Web, The 25th ACM Symposium on Applied Computing. 2009 Privacy and Security Steering Committee (2009-2011), Healthcare Information and Management Systems Society (HIMSS) Program Committee, 2009 AoT Security and Privacy Symposium Panelist, National Science Foundation (NSF), Directorate of Computer & Information Science & Engineering (CISE), Information and Intelligent Systems (IIS). Program Committee, The Secure Data Management (SDM) 2009 workshop. Program Committee, The IEEE International on Social Computing (SocialCom-09). Program Committee, The International Workshop on Context-Awareness Trust and Web 2.0 Trust. Program Committee, The First International ACM Workshop on Privacy and Anonymity for Very Large Datasets. Program Committee, The International Conference on Advances in Social Network Analysis and Mining. Program Committee, The 2nd International Workshop on Privacy and Anonymity in the Information Society (PAIS). Program Committee, The 12th IEEE International Enterprise Computing Conference Conference (EDOC) . 2008 Reviewer, Journal of Computer Security Program Committee, Third Workshop on Secure Knowledge Management (SKM) 2008. Program Committee, Workshop on Combining Context with Trust, Privacy and Security (CAT08), co-located with iTrust/PST (IFIPTM) conference. Program Committee, The 5th VLDB Workshop on Secure Data Management (SDM) 2008. Program Committee, The 12th IEEE International Enterprise Computing Conference Conference (EDOC) 2008. Program Committee, International Workshop on Privacy and Anonymity in the Information Society (PAIS) 2008. 2007 Program Committee, International Workshop on Privacy and Trust on the Web 2007. Program Committee, 1st International Workshop on Model-Based Trustworthy Health Information Systems (MOTHIS) 2007. Program Committee, The First ACM SIGKDD International Workshop on Privacy, Security, and Trust in KDD (PinKDD'07). Program Committee, 2nd International Workshop Dependability Aspects on Data Warehousing and Mining applications.                             Program Committee, 4th VLDB Workshop on Secure Data Management - with special session on security and privacy in healthcare Program Committee, IBM (Academy of Technology) Security & Privacy Symposium. Panelist, National Science Foundation (NSF), CyberTrust. Reviewer, Communications of the ACM. Reviewer, IEEE Transactions on Knowledge and Data Engineering. Reviewer, Journal of Systems and Software. 2006 Program Committee, Database Applications (DBA), IASTED. Program Committee, Dependability Aspects on Data Warehousing and Mining Applications (DAWAM). Program Committee, Secure Data Management(SDM). Program Committee, 1st International Conference on Belief Reasoning (IWBR2006). Reviewer, IEEE Transactions on Data and Knowledge Engineering Member of panel reviewing proposals, National scien Foundation. Program Committee, IBM Academy of Technology Symposium on Security and Privacy Reviewer, Transactions on Internet Research Reviewer, IEEE International Conference On Networking, Sensing and Control (ICNSC) Reviewer, ACM SIGMOD Reviewer, Encyclopedia of Database Technologies and Applications.