Privacy enhanced access control in pervasive computing environments

Privacy and security are two important but seemingly contradict objectives in pervasive computing environments (PCEs). On the one hand, service providers want to authenticate service users and make sure they are accessing only authorized services in a legitimate way. On the other hand, users want to maintain necessary privacy without being tracked down for wherever they are and whatever they are doing. In this paper we propose a novel privacy enhanced authentication and access control scheme to secure the interactions between mobile users and services in PCEs. The proposed scheme seamlessly integrates two underlying cryptographic primitives, blind signature and hash chain, into a highly flexible and lightweight authentication and key establishment protocol. It provides explicit mutual authentication between a user and a service, while allowing the user to anonymously interact with the service. Differentiated service access control is also enabled in the proposed scheme by classifying mobile users into different service groups.