POSN: A Cloud Based Privacy Preserving Decentralized Personalized Online Social Network

Abstract

As more users opt to use Online Social Networks (OSNs) to interact with friends and family, the privacy of the user is a growing concern. The current OSN architecture forces the user to trust the social network provider with his or her content, which can lead to privacy issues and concerns. When designing a new OSN, it is critical to understand how users interact over OSNs in order to provide the users with similar functionality while maintaining efficiency and privacy. Decentralized server architectures are an alternative that provide more privacy to the user by giving the user direct control of his or her content. Storage and data availability are a major concern in a decentralized system due to the burden of supplying resources is typically placed on the user. Cloud storage can be used to remedy that issue because it is available, and many cloud providers offer a significant amount of free storage to their users. As the usage of mobile devices is constantly growing, mobile devices can be paired with the clouds to create a decentralized social network. Encryption mechanisms can be used to guarantee that only the proper users can access the content, therefore enhancing the privacy.In this thesis, POSN, Personal Online Social Network, is introduced and takes a new approach for a privacy-preserving decentralized OSN platform. POSN is an Android application that utilizes both cloud storage and mobile devices to enhance the user's privacy. Symmetric and asymmetric encryption schemes are used to ensure data confidentially and provide fine-grain access control. A feasibility study was carried out to analyze the data transfer performance of the two popular social networks and five cloud storage providers to determine if clouds can be utilized to store and deliver content to users. The design of the POSN architecture is discussed in detail, including how the files in the system are structured. The implementation of the functionality available in POSN is also dicussed.