PPNP: A Privacy Profile Negotiation Protocol for Services in Public Spaces

In this paper, we propose Privacy Profile Negotiation Protocol (PPNP) that is a protocol for applying user’s privacy profile to services in public spaces to protect users from theft and leakage of privacy profile. In public spaces, third parties can provide services. This may cause malicious services to exist, which handle privacy profiles illegally. Thus, unintended third parties know privacy profiles. Basically, it is difficult for users to distinguish whether a service is malicious or not. In addition, a method aiming at justifying a service is not realistic, since the justifier must also be justified. Therefore a new mechanism that does not quite trust services is needed. To cope with this problem, PPNP incorporates granularity for representing privacy profiles. Users can mosaic their privacy profile offered to services coarse by changing the granularity. In this paper, we also describe PEGASUS that is a middleware designed for services in public spaces, which implements PPNP. We also mention PPM, which is a sample application of PEGASUS with PPNP.