Abstract
Routing in opportunistic network is a challenging issue due to its inherent characteristic. Absence of a continuous end-to-end connectivity in this network makes it difficult to establish a direct initial authentication from a sending node to a destination node. As a result, malicious devices join the opportunistic network posing different forms of security threats which makes the network vulnerable. This work performed a simulation to demonstrate the importance of security in opportunistic routing. An opportunistic network scenario analogy was further used to buttress the importance of security in the network. Simulation was carried out using the ONE simulator on the benchmark Helsinki simulation area. Two scenarios were considered; with and without malicious nodes. Result obtained showed that the presence of malicious devices decreased the delivery probability by 18% and increase the delay by 2196s when the same number of nodes were used. Also, results showed that a greater performance could be achieved with a fewer number of nodes free from malicious activity than with a higher number of nodes with malicious activity. This shows that security should be given paramount importance as it greatly affects the performance of the network.

Key words: Opportunistic routing, Network security, Security threats, Privacy.