Cryptographic Protocols for Enforcing Relationship-Based Access Control Policies

Relationship-based access control schemes have been studied to protect users' privacy in online social networks. In this paper, we propose cryptographic protocols for decentralized social networks to enforce relationship-based access control polices, i.e., K-common friends and k-depth. Our protocols are mainly built on pairing-based cryptosystems. We prove their security under the honest but curious adversary model, and we analyze their computation and communication complexities. Furthermore, we evaluate their efficiency through simulations on a real social network dataset.