Existing wireless network security mechanisms and their limitations for ad hoc networks

Unreliable wireless media, host mobility and lack of infrastructure present a big challenge to the provision of secure communications in mobile ad hoc networks. The contents of the communication must be encrypted and mutual authentication conducted between the communicating nodes in order to provide adequate security. Authentication protocols and key management techniques are utilised to provide security in many distributed systems. Much research has been conducted into the development of key management techniques and authentication protocols for WLAN (802.11b, 802.11i, 802.15.1, HIPERLAN) and traditional wireless networks (GSM, UMTS). This paper specifically describes the fundamental limitations of these underlying techniques and protocols and discusses why they cannot be directly employed in mobile ad hoc networks (MANETs). The paper also discusses security mechanisms already proposed for MANETs and outlines the research issues which still need to be explored in order to adequately address security concerns