An authorization-based trust model for multiagent systems

In this paper an authorization-based trust model (ABTM) is described which is designed for managing access to services in a semi-open distributed envi ronment. This is called a multiagent-based smart office environment. In thi s model, "trust" is defined as a set of authorization attributes that are g ranted by the owner of a service to the user of the service. Central to thi s model is a trust manager that redelegates authorizations from the service owner to the requesting user, based on access control policies that are sp ecified by role labels which are assigned to a set of agents. The ABTM sche me is different from a centralized scheme, in which authorizations are gran ted directly by an authority. It is also different from a fully distributed system, where authorizations are granted based solely on the discretion of the owner of the services. The design philosophy is the separation of trus t management and trust application to allow efficient management of access control in large-scale and dynamic environment, such as those that exist in multiagent systems.