Policies for Composed Emergencies in Support of Disaster Management

Recently, some proposals have appeared to achieve timely and flexible information sharing in support of emergency management. This is obtained by means of an emergency description language able to specify both emergency situations and temporary access control policies/obligations that have to be activated during emergencies. In this paper, we show that these languages have some limitations in capturing more critical emergency situations, which might arise when atomic emergency events are combined. Moreover, we show that such critical situations might require a new response plan (i.e., new temporary access control policies and obligations), with respect to those already in place for atomic emergencies. Therefore, we introduce the concept of composed emergency and related emergency policies. We also propose some overriding strategies to determine how temporary access control policies and obligations associated with a composed emergency have to be combined with those associated with atomic emergencies. Finally, we propose a tree-data structure in support of efficient emergency policy enforcement.