WSNs may be described as self-composed networks without the emergence of any fundamental regulator. Because of this property, protection and power consumption are main issues of WSNs. The security attacks are triggered by the malicious nodes which enter the network. Two categories of safety intrusions are active and passive. Sinkhole intrusion comes in the category of active intrusion. During sinkhole attack, the malicious nodes spoof identity of the base station and act like base station. The sensor nodes start transmitting data to malicious nodes instead of base station. In the existing system, the technique of monitor mode and mutual authentication are proposed for isolating the malicious nodes present in WSN. In the projected study, a novel approach is designed for detection and isolation of attacker sensor nodes from the system. Identity verification is the base of projected approach. Ns2 is used for the implementation of algorithm and results are analyzed in by means of throughput, package trouncing and power. Various investigations indicated that throughput of the projected technique is high in comparison with presented technique. The energy consumption of projected technique is fewer in comparison with accessible technique. Packet loss in case of existing technique is high as compared to proposed technique.