TrustSplit: usable confidentiality for social network messaging

Abstract

It is well known that online social networking sites (OSNs) such as Facebook pose risks to their users' privacy. OSNs store vast amounts of users' private data and activities and therefore subject the user to the risk of undesired disclosure. The regular non tech-savvy Facebook user either has little awareness of his privacy needs or is not willing or capable to invest much extra effort into securing his online activities. In this paper, we present a non-disruptive and easy to-use service that helps to protect users' most private information, namely their private messages and chats against the OSN provider itself and external adversaries. Our novel Confidentiality as a Service paradigm was designed with usability and non-obtrusiveness in mind and requires little to no additional knowledge on the part of the users. The simplicity of the service is achieved through a novel trust splitting approach integrated into the Confidentiality as a Service paradigm. To show the feasibility of our approach we present a fully-working prototype for Facebook and an initial usability study. All of the participating subjects completed the study successfully without any problems or errors and only required three minutes on average for the entire installation and setup procedure.