Title: TRUST IN ENFORCEMENT OF PRIVACY STATEMENTS

Trust in Enforcement of Privacy Statements

The European Directives 95/46/EC and 2002/58/EC demand the consent of users for a purpose-based processing of personal data according to informational self-determination. In practice, service providers publish the rules of their collection and usage of personal data by their privacy statement. Users agree to these rules if they want to use personalised services and thereby give their consent to the standard business conditions. An example for this practice are loyalty programmes (Müller and Wohlgemuth, 2007). 

Existing privacy enhancing technologies (PET) mainly follow the principle of data economy and do not focus on the enforcement of rules which correspond to disclosed data (Sackmann, Strüker and Accorsi, 2006). Identity management so far focuses in general on the disclosure and with the extension of delegation of rights (Wohlgemuth and Müller, 2006) also on the delegation of personal data where users act with pseudonyms. P3P (Cranor, Langheinrich, Marchiori, Marshall and Reagle, 2002) and EPAL (Ashley, Hada, Karjoth, Powers and Schunter, 2003) formalize privacy statements. But P3P does not consider rules (obligations) on the usage of personal data. EPAL supports obligations but does not offer a technical mechanism enabling users to control their enforcement. Consequently, users are not aware of rule violations. Disclosed personal data may be misused by service providers, e.g. used for other purposes or delegated to other services without the consent of the user.  

This current, one-sided trust model is shown in . The user discloses personal data d to a service provider which uses and delegates it in combination with user’s data d’ to other service provider. Users have to trust that these service providers follow the agreed rules for the processing of personal data d and d’.

Figure Current, one-sided trust model according to the model of (Pretschner, Hilty and Basin, 2006).