A secret sharing based privacy enforcement mechanism for untrusted social networking operators

Social networking sites (SNSs) have attracted millions of users. Through these sites, the users share their information (text messages, photos, and videos, etc) with their friends. By doing this, the privacy of users is often at stake. Although they provide some privacy settings to help in restricting access to a limited number of friends, they do not protect against the untrustworthiness of the social networking operator (SNO). Recently there has been some attempts to address this issue [1], [11]; these advocate for encrypting the users' data to ensure their privacy. However, these methods have their limitations. In [1], the security of the users' data is dependent on the non-disclosure of the encryption key; the scheme proposed in [11] is computationally expensive. In this paper, we propose a secret-sharing based key-management scheme for encrypting the users' data in order to preserve user's privacy. The proposed method offers unconditional security against the disclosure of the encryption key (to preserve privacy), and it is also computationally faster. The security of the method is analyzed against possible attacks, and the computational efficiency of the method is demonstrated using quantitative results.