ON MAXIMUM KEY POOL SIZE FOR A KEY PRE-DISTRIBUTION SCHEME IN WIRELESS SENSOR NETWORKS
Neeraj Mittal, T.R. Belagodu · International Journal of Computers and Applications · 2009
Bootstrapping secure communication among sensor nodes deployed in hostile environment is an important and challenging problem. A common approach to solve this problem is to use a key pre-distribution scheme in which each sensor node is assigned a subset of keys selected from some key pool. The resilience of a key pre-distribution scheme depends on the size of the key pool that the scheme uses for distributing keys among sensor nodes. After deployment, if two sensor nodes are within communication range of each other and share at least one common key, then they can establish a secure channel using the common key. We show that, when the key distribution is nearuniform, the maximum size a key pool that can be used by any key pre-distribution scheme is upper-bounded by s2 p, where s is the amount of space available on a sensor node for storing keys and p is the probability that two sensor nodes share a common The author is currently working as a software design engineer at Intel Corporation. 1 key. We define the notion of utilization factor of a key pre-distribution scheme to measure how effective the scheme is in using the largest key pool available at its disposal for fixed values of s and p. We explore the effect of the utilization factor of a scheme on its resilience. Key words: distributed systems, sensor nodes, wireless network, bootstrapping secure communication, key pre-distribution 1