Detecting Forged Acknowledgements in MANETs

Over the past few years, with the trend of mobile computing, Mobile Ad hoc Network (MANET) has become one of the most important wireless communication mechanisms among all. Unlike traditional network, MANET does not have a fixed infrastructure, every single node in the network works as both a receiver and a transmitter. Nodes directly communicate with each other when they are both within their communication ranges. Otherwise, they rely on their neighbors to store and forward packets. As MANET does not require any fixed infrastructure and it is capable of self configuring, these unique characteristics made MANET ideal to be deployed in a remote or mission critical area like military use or remote exploration. However, the open medium and wide distribution of nodes in MANET leave it vulnerable to various means of attacks. It is crucial to develop suitable intrusion detection scheme to protect MANET from malicious attackers. In our previous research, we have proposed a mechanism called Enhanced Adaptive Acknowledgement (EAACK) scheme. Nevertheless, it suffers from the threat that it fails to detect misbehaving node when the attackers are smart enough to forge the acknowledgement packets. In this paper, we introduce Digital Signature Algorithm (DSA) into the EAACK scheme, and investigate the performance of DSA in MANET. The purpose of this paper is to present an improved version of EAACK called EAACK2 that performs better in the presence of false misbehavior and partial dropping.