Reclaiming Location Privacy in Mobile Telephony Networks—Effects and Consequences for Providers and Subscribers

Mobile telephony (e.g., Global System for Mobile Communications [GSM]) is today´s most common communication solution. Due to the specific characteristics of mobile communication infrastructure, it can provide real added value to the user and various other parties. Location information and mobility patterns of subscribers contribute not only to emergency planning, general safety, and security, but are also a driving force for new commercial services. However, there is a lack of transparency in today´s mobile telephony networks regarding location disclosure. Location information is generated, collected, and processed without being noticed by subscribers. Hence, by exploiting subscriber location information, an individual´s privacy is threatened. We develop a utility-based opponent model to formalize the conflict between the additional utility of mobile telephony infrastructure being able to locate subscribers and the individual´s privacy. Based on these results, measures were developed to improve an individual´s location privacy through a user-controllable GSM software stack. To analyze and evaluate the effects of specific subscriber provider interaction, a dedicated test environment will be presented, using the example of GSM mobile telephony networks. The resulting testbed is based on real-life hardware and open-source software to create a realistic and defined environment that includes all aspects of the air interface in mobile telephony networks and thus, is capable of controlling subscriber-provider interaction in a defined and fully controlled environment.