Offering a holistic approach to social computing with respect to the underlying theory, technology and mechanisms, this book also examines the challenges, opportunities and impact of social computing to any application area.
Showcasing cutting-edge research on the intersections of Semantic Web, collaborative work, and social media research, this book will be of great use to those aiming to research and develop collaborative systems and applications that build on semantic technologies.
User-to-user (U2U) relationship-based access control has become the most prevalent approach for modeling access control in online social networks (OSNs), where authorization is typically made by tracking the existence of a U2U relationship of particular type and/or depth between the accessing user and the resource owner. However, today’s OSN applications allow various user activities that cannot be controlled by using U2U relationships alone. In this paper, we develop a relationship-based access control model for OSNs that incorporates not only U2U relationships but also user-to-resource (U2R) and resource-to-resource (R2R) relationships. Furthermore, while most access control proposals for OSNs only focus on controlling users’ normal usage activities, our model also captures controls on users’ administrative activities. Authorization policies are defined in terms of patterns of relationship paths on social graph and the hop count limits of these path. The proposed policy specification language features hop count skipping of resource-related relationships, allowing more flexibility and expressive power. We also provide simple specifications of conflict resolution policies to resolve possible conflicts among authorization policies.
Web-based social networks (WBSNs) are today one of the hugest data source available on the Web and therefore data protection has become an urgent need. This has resulted in the proposals of some access control models for social networks. Quite all the models proposed so far enforce a relationship-based access control, where the granting of a resource depends on the relationships established in the network. An important issue is therefore to devise access control mechanisms able to enforce relationship-based access control by, at the same time, protecting relationships privacy. In this paper, we propose a solution to this problem, which enforces access control through a collaboration of selected nodes in the network. We exploit the ElGamal cryptosystem to preserve relationship privacy when relationship information is used for access control purposes.
Social Networks were created to allow users to maintain circles of friends and acquaintances. Over time, they have come to be used to share data objects such as pictures between friends. There have been several approaches to formalize social networks in order to specify complicated access control policies for such objects. These approaches have involved a combination of existing logic with custom languages, with new operators being introduced when more complex policies needed to be expressed. In this paper we demonstrate that set theoretic notation provides a convenient syntax for specifying a social network and the associated access control policies. We demonstrate that our notation enables us to extend the range of policies that can be articulated. We also demonstrate that our notation is simpler and more concise than existing approaches.
Addressing fundamental questions about how the social, economic, and technological worlds are connected, this book examines the links that connect us and the ways in which our decisions can have subtle consequences for others.