Future directions and conclusion

© Springer Nature Switzerland AG 2019. While previous chapters provide a thorough description on malicious attack propagation and source identification, many interesting and promising issues remain unexplored. The development of online social networks provides great opportunities for research on restraining malicious attacks and identifying attack sources, but also presents a challenge in effective utilization of the large volume of data. There are still other topics that need to be considered in malicious attack propagation and source identification, and we consider a few directions that are worthy of future attention.