Wireless sensor networks are now-a-days rapidly developing in the field of science and technology. And it promises to have a large number of applications in Next Generation Networks (NGNs). The wireless sensor networks can be easily attacked from various sides and one of the serious attacks faced by the wireless sensor networks is the node clone attack. The node clone attack acts as the basic method to mount a huge insider attack. The cloned nodes must be detected in order to minimize the damages caused by them to the network. To protect the network from the clone attacks is to prevent an adversary from extracting the secret key materials from the captured node.