In this paper, we describe the software architecture of a commercially run home assistance system that allows patients or elderly people to stay longer at home. Since such systems often have to handle sensitive medical information, the protection of the privacy is a major concern. Also, legislation often restricts access to health information to qualified persons (i.e. medical personnel), who are not always available in a commercial company.The home assistance system can offer several services, going from scheduling necessary tasks and following up their execution, to monitoring the patient’s health status and responding promptly to requests for help or to emergency situations, and all this without the need to maintain personal medical data or identifying information in the home assistance center.This paper focusses on how the commercial home assistance center will keep track of the anonymized patients’ networks. A network consists of all the caregivers of a patient; each member of the network has been assigned a role, which is used in course-grained authorization decisions. The protocols involve anonymous credentials for the caregivers and smartcards for patients.