Wireless sensor networks can provide low cost solution to verity of real-world problems. Sensors are low cost tiny devices with limited storage, computationalcapability and power. They can be deployed in large scale for performing both military and civilian tasks. Security will be one of the main concerned when they will be deployed in large scale.
As sensors have limited power and computational apability, any security mechanism for sensor network must be energy e±cient and should not be computationalintensive.
In this thesis we propose an energy-e±cient secure routing for wireless networks based on symmetric key cryptography. The proposed crypto system is session based and the session key is changed after the expire of each session. We divide the network into number of clusters and select a cluster head within each cluster.Communication between sensor and the sink takes place at the three level; sensor!
cluster-head ! sink. Encryption of the sensed data is ransmitted to the cluster head, which aggregated the data received from the sensor nodes of its cluster before forwarding to the next cluster head on the path or to the sink . Sensors do not participate in the routing scheme; their energy is conserved at each sensor
node
