Security attacks in Opportunistic Mobile Networks: A systematic literature review

Opportunistic Mobile Networks (OMNs), also known as Delay Tolerant Networks (DTNs), refer to wireless networks in which the mobile nodes (e.g., smartphones, tablets, notebooks, laptops) are intermittently and opportunistically connected (when the nodes encounter each other). The opportunistic connectivity of the nodes and their ability to join/leave at anytime makes OMNs/DTNs exposed to different kinds of security attacks. Moreover, OMNs/DTNs have been employed in a wide range of applications such as disaster response scenarios, battlefield/military communications, monitoring marine life, and social networks applications. Hence, researchers have identified and studied different security attacks in OMNs/DTNs and proposed several countermeasures/approaches to address (detect, mitigate, and/or prevent) these attacks. To further help future researchers, in this paper, a systematic literature review is conducted to survey the research articles that studied the impacts of four major security attacks (Blackhole, Wormhole, Sybil, and Denial-of-Service) in OMNs/DTNs and the proposed detection/defense mechanisms to address them. To the best of our knowledge, this is the first systematic literature review that is based on a predefined search methodology and systematically collects the relevant research articles that were published between 2011 and 2023. After applying the systematic search methodology, 45 research articles were extracted and surveyed that resulted with a redefined taxonomy of the security attacks. Moreover, the authors summarized the proposed detection/defense mechanisms and provided a comparison among them based on their basis, objective(s), attacker models, and performance methodologies/metrics. This survey also provides a discussion of the research gaps and proposes several research topics, challenges, and recommendations to be investigated and addressed by future work.