My research focuses on networking, security and trust. I am particularly interested in new network architectures as response to the changing challenges and needs of users in various environments and applications, such as Internet, wireless, optical, multimedia, and so on. Important design goals for such systems include scalability, security, robustness, reliability, economic viability, manageability. My research explores the design space among various goals and constrains and tries to find desirable tradeoffs, which would enable the practical use of new solutions. Furthermore, I work to develop trust management systems,by using measurement theory to evaluate trust.