Random Bit Extraction for Secret Key Generation in MANETs

Mobile ad hoc networks are a group of random mobile nodes which does not have a pre-existing base stations or infrastructure. In order to make communications effective over these networks a security scheme is essential. This can be achieved by establishing some shared random bits generated with fundamental secret key generation techniques. This paper presents a secret key generation scheme suitable for networks adapted to dynamic source routing protocol. Investigations were carried out for the possibility of using a system metadata like routing information for randomness extraction. Using routing tables maintained by the nodes as backbone, we are extracting a set of common secret random data for key generation. The secret key generation starts with random source extraction followed by information reconciliation to reduce errors and privacy amplification to increase the confidentiality. The main advantage of this technique is that it utilizes the sources of randomness inherent in the system itself without increasing the computational complexity. It also helps to identify the presence of an adversary in the network. The results of the system are evaluated to analyze the efficiency of the technique in terms of packet loss and packet overhead.