A Taxonomic Study of the Recent Security Concerns in Opportunistic Networks

Opportunistic networks contain mobile nodes with wireless networking capability which deliver messages in a hop-by-hop fashion completely based on local information and using opportunistic connectivity created due to device proximity. There exists no predefined path between the source and destination. The source only forwards the data to the next node based on its capability to carry the data packet one step closer to the destination. Due to the absence of any concrete path connected by trustful nodes, these types of networks suffer from a number of security issues. The intermediate nodes may be malicious and lead to loss of packets, breach of user privacy, compromising data confidentiality by unwanted intrusion etc. General cryptography algorithms cannot be applied here directly due to the absence of any end-to-end secure path. The nodes have to solely depend on the next hop node for data transfer. So there is a need of such security mechanisms which would ensure that the intermediate nodes do not behave maliciously. This survey is an attempt to study and compare some security techniques being applied to Opportunistic Networks so far.