· security of wireless sensor network are given

·         Military applications : In military wireless sensors is used in various domains, they generally do enemy tracking, battlefield surveillance or classification of target. They can also be used for enemy tracking in wartime scenarios and can be used in peace time.

·         Environmental monitoring : Wireless sensors can also be used in indoor environmental monitoring and outdoor monitoring. There are major waste of energy occurs through unnecessary heating and cooling of buildings, deployed nodes can help in reducing the wastage of energy. These nodes can also help to observe environmental conditions inside buildings that can help in mitigation of earthquake and fire.

·         Health care system : Wireless sensors can also help in the domain of health care system and health science. The nodes can be used to record the frequent actions (taking medications, last visitors) or detect emerging problem. These sensors are also implanted to human organ and help to communicate wirelessly with an external computer system that provide some crucial information regarding the patient.

·         Infrastructure security : Sensor networks can be utilized for framework security also for counterterrorism applications. Basic structures and offices, for example control plants and communication centers must be shielded from potential terrorists. Network of video, underwater, and different sensors can be sent around these facilities. These sensors give early recognition of conceivable dangers 3.

1.4 Security Problems In WSN

Wireless networks are very much vulnerable because of their deployment in open and unattended environment. Some of issues in security of wireless sensor network are given below4:

·         Limited Hardware: The sensor nodes are exceptionally little and in the current patterns there is prerequisite to expand the lifetime of nodes by diminishing the data transmission, memory and so on. Because of these constrained resources, setting up security among these nodes is a very difficult task.

·         Wireless communication: The communication medium is costlier and it is more powerless to dangers like eavesdropping, embeddings malicious nodes into the system, flooding and so on. Because of wireless medium, we can’t select protocols that require trade of more data or message.

·         Hostile Environment: Since the sensor nodes are conveyed to unattended zones, the intruder or attacker can get to the nodes and change the collected information. The nodes are not totally safe because of its high cost which likewise gives a simple intends to get access to the nodes.

Aggregation processing: Sensor nodes get the data from every other link (sensor node) across the network and sends the data to the destination. The lifetime of the sensor nodes can be expanded by decreasing the correspondence communication between the nodes. But it can’t be implemented in practical since the sensor nodes must communicate to perform data processing4