Data protection and privacy is rapidly becoming one of the most important issues on the Internet today. Larger number of Internet sites are collecting personal information from users through forms, cookies, online registrations, or surveys than ever before. New commercial services are springing up that can exploit the ability of mobile communication service providers to determine the geographic location of their users. The new wireless technologies offer mobility; at the same time they offer location information that is being used to provide new location-aware services.

This licentiate thesis concerns our experience building a new innovative network environment at the IT-University (Royal Institute of Technology). It explains how we present the new security challenges that a wireless network raises together with how we confront and investigate a new form of problem this type of network presents, namely location privacy.

The focus of this work has been on trying to provide unlinkability between the location of wireless users and their activities in the Internet. The thesis includes a protocol extension to a pseudonymous IP network architecture developed by the Canadian company Zero Knowledge Systems Inc. called the Freedom System. The proposed extension to Freedom System permits a mobile client to seamlessly roam among IP subnetworks and media types whilst being untraceable. By untraceable in the context of this thesis we mean the capability of a mobile node to conceal the relation between location and personal identifiable information from third parties whilst the user is on the move.

This thesis is composed of four published papers where the main results are presented.