Model and service for privacy in decentralized online social networks

Intensely using online social networks (OSNs) makes users concerned about privacy of data. Given the centralized nature of these platforms, and since each platform has a particular storage mechanism, authentication, and access control, their users do not have the control and the right over their data. Therefore, users cannot easily switch between similar platforms or transfer data from one platform to another. These issues imply, among other things, a threat to privacy since such users depend on the interests of the service provider responsible for administering OSNs. As a strategy for the decentralization of the OSNs and, consequently, as a solution to the privacy problems in these environments, the so-called decentralized online social networks (DOSNs) have emerged. Unlike OSNs, DOSNs are decentralized content management platforms because they do not use centralized service providers. Although DOSNs address some of the privacy issues encountered in OSNs, DOSNs also pose significant challenges to consider, for example, access control to user profile information with high granularity. This work proposes developing an ontological model and a service to support privacy in DOSNs. The model describes the main concepts of privacy access control in DOSNs and their relationships. In addition, the service will consume the model to apply access control according to the policies represented in the model. Our model was evaluated in two phases to verify its compliance with the proposed domain. Finally, we evaluated our service with a performance evaluation, and the results were satisfactory concerning the response time of access control requests.