Both the significance and use of the World Wide Web (WWW) have increased in recent years. It has evolved from a service which provided scientific content initially for the academic world to a fairground for diverse providers and information, some of which are of dubious nature. The desire for anonymity is therefore great; while surfing on the internet users leave numerous traces of information behind which are so significant that a profile based on their behavior can be made. The compilation of such information is not only a violation of security regulations but is also a violation of personal rights and can be used for illegal purposes (collecting addresses, profiling personal preferences). This is why there are several services which allow WWW users to “hide” behind them, and remain anonymous. The possibilities which ensure individual anonymity and the development of such mechanisms were the main focus of research at the department. Alongside the perspective of protecting the user of a service, looking at this issue from the viewpoint of the provider of information is a relatively new development.