R. Karthikeyan
There are several emerging trends in the field of networks, out of which Wireless Sensor Networks(WSN) are gaining importance recent years due to its impact on Cost, ability to cope up with node and communication failures, Mobility, Capability to withstand harsh environmental condition, monitoring purpose and Ease of use. Despite Sensor nodes large collection of benefits there are few constrains such as Security, Quality of Service and Resource constrains which act as hurdle in implementing sensor network application in real world environment. Security is considered to be a critical parameter in Sensor network due to the fact that they are mostly deployed in an environment where human interaction is less. An opponent or intruder is one who may perform various attacks on packets in order to make a node compromise and cut short the communication to take place. Attacks that have been concentrated here are packet dropping and modification. Sensor applications are time critical and if compromised nodes are not detected, large quantities of irrelevant data can be injected into the network which in turn will have a greater impact on computational cost and storage overhead. In this paper Node Categorization and Heuristic Ranking (NCHR) is used along with our proposed scheme of energy consumption and delay aspects to identify compromised nodes and further a Secure Routing and Encryption techniques are provided to ensure reliable communication.