Virtual energy based distributed security for wireless sensor networks

Node compromise is a serious threat in wireless sensor networks. Once a node is compromised an adversary can inject false data into the network and drop the data by pinpointing to a particular route. In this paper a scheme based on virtual energy based encryption using RC4 encryption mechanism is presented. The key to the RC4 encryption mechanism dynamically changes as the function of the residual virtual energy of the sensor changes. This residual virtual energy gets depleted as the node traverses different functional states. Thus different keys are generated based on the current residual virtual energy of the sensor node for successive data transmission. The sensed data is encrypted using RC4 algorithm and propagates from source node to the cluster head using randomized multipath algorithm Due to the random propagation of data, even if the adversary pin points to a particular route he cannot collect all the data since, it takes different path for the same source node to the cluster head each time. The cluster head verifies the authenticity and integrity of the incoming data using the predicted value of the key generated by the sender´s virtual energy and forwards the data to sink, thus preventing the need for any control messages for key exchange. The simulation result shows that the average end to end delay and packet loss probability remain constant for any number of nodes and for varying no of event regions.