Observation-based trust management for services in mobile networks

The growing availability of well-equipped handheld devices and the increasing mobility of users influence the way today's services can be used. In the future, services provided by different devices can be used on an ad-hoc basis to fulfill user-specified tasks. This chapter proposes an infrastructure for mobile networks that allows for the rating of nodes with respect to their provided functionalities. Thus, it is possible to create reputation relationships and trust assessments between service requesters and service providers. One means for making use of trust relationships is in the reduction and the prevention of interactions with misbehaving or inaccurate nodes. The authors' work also factors in the subjectivity of users by allowing different service quality perceptions for each user. Thus, each user can base his or her cooperation behavior on their own service behavior preferences instead on the aggregated preferences of all users.