Wireless Sensor Networks (WSN) is a leading technology these days and has a broad variety of application such as battleground supervision, traffic surveillance, flood finding, forest fire discovery etc. But wireless sensor networks are vulnerable to a multiplicity of possible attacks which hamper the normal process of the system. Selective forwarding and Black hole attack are most harsh security hazards that have an effect on the network from its regular functioning by unkindly advertising itself surrounded by shortest path to the targeted node and then drops all in receipt of packets. There be a lot of methods have been projected to preserve network from selective forwarding and black hole attack, but not any of the methods looks most capable to defend alongside these attacks. So in this paper, we have examined the existing justification for selective forwarding and black hole attacks using different protocol.

Keywords : WSNs; Security; Selective Forwarding Attack; Blackhole Attack; Attacks;