EPF: An event-aided packet forwarding protocol for privacy-preserving mobile healthcare social networks

In this paper, we propose an event-aided packet forwarding (EPF) protocol, which enables patients to efficiently communicate with each other in privacy-preserving Mobile Healthcare Social Networks (MHSNs). Since patients with common illnesses often attend the same related activities, EPF makes use of these activities in forwarding illness-related messages to the target patients so that it can achieve high target patients coverage ratio. In addition, EPF also adopts predicate encryption to guarantee patient privacy and message confidentiality. Through security analysis, we demonstrate that EPF can effectively resist various attacks launched by adversaries, and ensure patient identity and illness privacy. Extensive simulations are also conducted to evaluate the performance of EPF in terms of average target patients coverage ratio, average number of packet copies, and average packet delay.