The popularity of online social networks (OSNs) makes the protection of users' private information an important but scientifically challenging problem. In the literature, relationship-based access control schemes have been proposed to address this problem. However, with the dynamic developments of OSNs, we identify new access control requirements which cannot be fully captured by the current schemes. In this paper, we focus on public information in OSNs and treat it as a new dimension which users can use to regulate access to their resources. We define a new OSN model containing users and their relationships as well as public information. Based on this model, we introduce a variant of hybrid logic for formulating access control policies. We exploit a type of category information and relationship hierarchy to further extend our logic for its usage in practice. In the end, we propose a few solutions to address the problem of information reliability in OSNs, and formally model collaborative access control in our access control scheme.
proposed an access control scheme for Facebook-style social networks @cite_30 , in which they model the access control procedure as two stages. In the first stage, the requester has to find the owner of the target resource; then in the second one, the owner decides whether the authorization is granted or not. Their access control policies are mainly based on the relationships between the requester and the owner. Moreover, they proposed several meaningful access control policies based on the graph structure of OSNs, such as @math -common friends and clique. @cite_8 , Fong introduced a modal logic to define access control policies for OSNs. Later Fong and Siahaan @cite_21 improved the previously proposed logic to further support policies like @math -common friends and clique. @cite_11 , the authors adopted a hybrid logic to describe policies which eliminates an exponential penalty in expressing complex relationships such as @math -common friends. A visualization tool for evaluating the effect of the access control configurations is designed in @cite_0 , with which a user can check what other users within a certain distance to him can view his resources.
@cite_30 @cite_8 @cite_21 @cite_0 @cite_11
1986789125 1530514231 1998591172 2063703813
In this paper we introduce a novel scheme for key management in social networks that is a first step towards the creation of a private social network. A social network graph (i.e., the graph of friendship relationships) is private and social networks are often used to share content, which may be private, amongst its users. In the status quo, the social networking server has access to both this graph and to all of the content, effectively requiring that it is a trusted third party. The goal of this paper is to produce a mechanism through which users can control how their content is shared with other users, without relying on a trusted third party to manage the social network graph and the users' data. The specific access control model considered here is that users will specify access policies based on distance in the social network; for example some content is visible to friends only, while other content is visible to friends of friends, etc. This access control is enforced via key management. That is for each user, there is a key that only friends should be able to derive, there is a key that both friends of the user and friends of friends can derive, etc. The proposed scheme enjoys the following properties: i) the scheme is asynchronous in that it does not require users to be online at the same time, ii) the scheme provides key indistinguishability (that is if a user is not allowed to derive a key according to the access policy, then that key is indistinguishable from a random value), iii) the scheme is efficient in terms of server storage and key derivation time, and iv) the scheme is collusion resistant. The popularity of online social networks (OSNs) makes the protection of users' private information an important but scientifically challenging problem. In the literature, relationship-based access control schemes have been proposed to address this problem. However, with the dynamic developments of OSNs, we identify new access control requirements which cannot be fully captured by the current schemes. In this paper, we focus on public information in OSNs and treat it as a new dimension which users can use to regulate access to their resources. We define a new OSN model containing users and their relationships as well as public information. Based on this model, we introduce a variant of hybrid logic for formulating access control policies. We exploit a type of category information and relationship hierarchy to further extend our logic for its usage in practice. In the end, we propose a few solutions to address the problem of information reliability in OSNs, and formally model collaborative access control in our access control scheme. 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. In this article, we propose an access control mechanism for Web-based social networks, which adopts a rule-based approach for specifying access policies on the resources owned by network participants, and where authorized users are denoted in terms of the type, depth, and trust level of the relationships existing between nodes in the network. Different from traditional access control systems, our mechanism makes use of a semidecentralized architecture, where access control enforcement is carried out client-side. Access to a resource is granted when the requestor is able to demonstrate being authorized to do that by providing a proof. In the article, besides illustrating the main notions on which our access control model relies, we present all the protocols underlying our system and a performance study of the implemented prototype.