The rapid growth of Internet usage raised concerns over the privacy of communication and information dissemination. For example, Number of online advertising companies uses traffic analysis to learn the browsing habit of the target users and launch the advertisements accordingly. Corporate companies could use traffic analysis to monitor, when the competitor visits its website, and track what pages or products that interest the competitor. And the privacy loses in defense organizations matters more. Anonymous communication is a way to enhancing privacy and making the traffic analysis more difficult. In this seminars I will present the overview of various forms of anonymous communication and how it will enhance the privacy.