Abstract: Wireless sensor networks are consisting large number of sensor nodes which are limited to sensing, computing, processing the data and communication capability. Due to these limitations it is important to minimize the amount of data transmission so the average lifetime of network and bandwidth utilization improved as well minimize the computational power at every node in order to improve lifetime of network. WSNs are deployed in remote and open environment to transmit the sensitive information, and sensor nodes are easily prone to malicious activity of the attackers so security is most important. Hence, wireless sensor networks protocols must be designed with security in mind. This paper presents protocol, which merely detect the Blackhole attacks from network itself and take appropriate decision so the performance of the network can be improve.

Keywords: Wireless Sensor Networks (WSNs), Data Aggregation, Security Objectives, Attacks, Routing Protocols.