A Privacy Enhancement Mechanism for Location Based Service Architectures Using Transaction Pseudonyms

Third party service providers are starting to use advanced location services based on area or periodical notification in order to develop innovative applications. However, such functions can be easily misused for tracking users and building their activity profiles, if privacy enhancement mechanisms are not integrated into the service architecture. In this paper we present a protocol based on transaction pseudonyms that protects the user's address from being disclosed and associated with their location. Based on hash chains, the pseudonyms are used to authorize service and the localization requests, making possible ad hoc service usage without registration. We further analyze security aspects of the proposed protocol.