Sensor networks consist of a large number of sensors that monitor the environment, and a few base stations that collect the sensor readings. Security services such as authentication and key management [1] are critical to secure the communication between sensor nodes in hostile environments. Sensor nodes may establish keys between each other through key predistribution, where keying materials are predistributed to sensor nodes before deployment. Pre-distribution of secret keys for all pairs of nodes is not viable due to the large amount of memory used when the network size is large. If we know which nodes are more likely to stay in the same neighborhood before deployment, keys can be decided a priori. There exist a number of key pre-distribution schemes. A naive solution is to let all the nodes carry a master secret key. Any pair of nodes can use this global master secret key to achieve key agreement and obtain a new pairwise key[2,3]. Another key pre-distribution scheme[4] is to let each sensor carry N − 1 secret pairwise keys, each of which is known only to this sensor and one of the other N−1 sensors (assuming N is the total number of sensors).Symmetric key agreement is significant to security provisioning in sensor networks with resource limitations. A number of pairwise key predistribution protocols have been proposed, but the performance is often constrained by the unavailability of topology information before deployment and the limited storage budget within sensors. SGKP, a self-configured scheme for bootstrapping keys in large-scale sensor networks. SGKP is topology-adaptive, which requires no preloaded keying information but lets sensors compute shared keys with their neighbors after deployment.

Key predistribution Self configured scheme Pairwise Key Service node Worker node