Access control in wireless sensor networks

Nodes in a sensor network may be lost due to power exhaustion or malicious attacks. To extend the lifetime of the sensor network, new node deployment is necessary. In military scenarios, adversaries may directly deploy malicious nodes or manipulate existing nodes to introduce malicious "new" nodes through many kinds of attacks. To prevent malicious nodes from joining the sensor network, access control is required in the design of sensor network protocols. In this paper, we propose an access control protocol based on Elliptic Curve Cryptography (ECC) for sensor networks. Our access control protocol accomplishes node authentication and key establishment for new nodes. Different from conventional authentication methods based on the node identity, our access control protocol includes both the node identity and the node bootstrapping time into the authentication procedure. Hence our access control protocol cannot only identify the identity of each node but also differentiate between old nodes and new nodes. In addition, each new node can establish shared keys with its neighbors during the node authentication procedure. Compared with conventional sensor network security solutions, our access control protocol can defend against most well-recognized attacks in sensor networks, and achieve better computation and communication performance due to the more efficient algorithms based on ECC than those based on RSA.