Location privacy in the Alipes platform

An increasing number of systems use contextual information about their users. Such contextual information can be used to design applications that survey usage and adapt thereafter, or simply just use context information to optimize presentation. Context information could therefore be used to create applications for the benefit of the users of the system, but the same information could cause serious violations of personal integrity if misused. Locality may be the most widely used, but also the most sensitive contextual information. The Alipes platform makes it easy to create location-based services while enforcing user privacy and integrity. The platform handles privacy through rules that describe how and under what circumstances a user's context may be distributed to other users, for example rules describing limitations concerning the user's context, a certain time period, the number of queries and the type of applications. This paper presents how location privacy is enforced in the Alipes platform.