Detecting and Defending against Sybil Attacks in Social Networks: An Overview

Sybil attacks are becoming increasingly serious in online social networks. A number of schemes to defend against Sybil attacks have been developed in the past decade. However, only a few of these schemes are widely used in real-world social networks. In this article, we provide an overview of the key challenges in detecting and defending against Sybil attacks and the work performed so far. We aim to provide inspiration to future researchers who wish to overcome the said challenges. This study lays a foundation for the development of defence schemes and their application in real-world social networks.