Abstract
In the real environment, nodes in a sensor network need to communicate securely. In order to achieve that, there are different methods that can be used for encryption, decryption and authentication. Due to the resource constraints of sensor nodes, some of these methods, such as RSA and Diffie-Hellman base schemes, cannot be applied. Also storing a secret key for every node in the network is not suitable for large size networks. Recently, several key pre-distribution schemes were proposed, such as the random key pre-distribution scheme, the q-composite random key pre-distribution scheme, multi-path key reinforcement, and the random-pairwise keys scheme.
The random-pairwise keys scheme has several advantages over other schemes, such as node-to-node identity authentication, and high resilience against node capture. On the other hand, the number of keys that should be stored in a node using the random-pairwise keys scheme increases when the number of nodes in the network increases, which means that when the number of nodes is high the node will not be able to store the required number of keys. This drawback can be overcome by using deployment knowledge, which is the knowledge that we can get about the distribution of the nodes from knowing the deployment method.
In this paper, we propose a new scheme that uses deployment knowledge to avoid unnecessary key assignments and to make the number of keys in a node depend on the density of the nodes rather than on the number of nodes in the network, also we show the performance evaluation of the network.