Date Added: Aug 2012
Many sensor networks (especially networks of mobile sensors or networks that are deployed to monitor crisis situations) are deployed in an arbitrary and unplanned fashion. Thus, any sensor in such a network can end up being adjacent to any other sensor. In the network. To secure the communications between every pair of adjacent sensors in such a network, each sensor x in the network needs to store n - 1 symmetric keys that sensor x shares with all the other sensors, where n is the number of sensors in the network. This storage requirement of the keying protocol is rather severe, especially when n is large and the available storage in each sensor is modest.