An Extended Model for Group-Centric Secure Information Sharing

In this paper, we propose an extended model for Group-Centric Secure Information Sharing (g-SIS) not only based on the temporal ordering of subject and object group membership but also on the privileges of the subject. The traditional approach to information sharing focuses on attaching attributes and policies to an object as it is disseminated from producers to consumers in a system. In contrast, group-centric sharing envisions bringing subjects and objects together in a group to facilitate sharing. In such contexts, Krishnan thinks that authorizations are influenced by the temporal ordering of subject and object group membership. For instance, some subjects may only get future information added to the group while others may also be able to access previously added information. We think that authorizations are also influenced by the privileges of the subject except for the temporal ordering of subject group membership. Thus, we develop a model based on the temporal ordering of group membership and the privileges of the subject and give its temporal logic specification. And we discuss usage scenario to illustrate the practical application in subscription system.