iSac: Intimacy Based Access Control for Social Network Sites

Participation in social networking sites has dramatically increased in recent years. Users on social networking sites spend lots of time generating large quantities of various personal content items (eg. diaries, albums, and comments) and browsing these varieties of content everyday. However, existing social networking sites do not provide effective access control mechanisms to assure the privacy of user-generated content. A user's personal content on social networking sites may be exposed to other users without any access control. This paper presents iSac, a novel intimacy-based social access control mechanism on social networking sites. iSac allows a user to make his access control policy on social networking sites according to intimacy degrees of him with respect to other users. iSac will first outline a user's activity profile according to his atomic social activities with respect to his seed friends. Then we adopt Naive-Bayes algorithm to calculate the intimacy degrees and rankings of all the user's friends. A content owner can make his access control policy by assigning a range of intimacy degrees. Users whose intimacy degrees are in the acceptable range can visit the content owner's personal content. Our experiments which use data collected from Ren Ren in China prove that iSac can effectively differentiate a user's friends by intimacy degrees so as to provide a novel access control mechanism with an improved granularity.