PRECISE: Identity-based private data sharing with conditional proxy re-encryption in online social networks

Online social networks (OSNs) have become popular around the world due to its openness. Although cryptographic techniques can provide privacy protection for users in OSNs, several issues also remain problematic, such as fine-grained access control, efficiency and usability. In this paper, we propose PRECISE, an identity-based private data sharing scheme in OSNs with big data, in which the data owner could broadcast private data to a group of users at one time in a convenient and secure way. In order to achieve secure and fine-grained data disseminating in OSNs, we adopt attribute-based conditional proxy re-encryption to guarantee that only the data disseminators whose attributes satisfy access policy can disseminate the data to their own social space. The re-encryption key is associated with a set of attributes such that only the matched ciphertexts can be re-encrypted, which allows data owner to enforce access control over the disseminated ciphertexts in a fine-grained manner. The secure and performance analysis shows our scheme is secure and efficient. (C) 2017 Elsevier B.V. All rights reserved.