Sunday, August 1, 2004

A focus on the challenges of mobile ad-hoc networks

WIRELESS INFRASTRUCTURE

By Humayun Bakht

Our future living environments are likely to be based upon information resources provided by the connections of various communication networks for users. New devices like personal digital assistants, mobile phones and handhelds are advancing information processing and accessing capabilities with mobility. Moreover, traditional homes appliances and "gadgets," such as digital cameras, washing machines, cooking ovens and refrigerators -- with computing powers attached -- will extend the field to a fully pervasive computing environment. In the near future, mobile computing environments are expected to be based on recent advancements in computing and mobile technology. Next generation mobile systems will include both infrastructured wireless networks and infrastructureless mobile ad-hoc network.

A peer-to-peer or a mobile ad-hoc network is a collection of mobile nodes connected together over wireless medium without any fixed infrastructure. The special features of mobile ad-hoc networks bring the technology great opportunities together with different challenges. Challenges in the area of mobile ad-hoc network include security, dynamic network topology, routing, quality of service, and power efficiency.

One of the primary concerns is to provide secure communication between mobile hosts in a hostile environment. Unique characteristics of mobile ad-hoc networks pose various challenges to the security design, such as open peer-to-peer network architecture, a shared wireless medium and a high dynamic topology. These challenges raised the requirement of developing security solutions that achieve wider protection and desirable network performance. The wireless channel in a mobile ad-hoc network is accessible to both legitimate network users and malicious attackers. There is no standard security mechanism in a mobile ad-hoc network from the security design perspective to address this issue.

Since mobile ad-hoc networks do not have any centrally administrated secure routers, chances are good that attackers can easily exploit or possibly disable a mobile ad-hoc network, if no security mechanism is adopted. In general, security goals in mobile ad-hoc networks are gained through cryptographic mechanisms, such as public key encryption or digital signature. These mechanisms are supported through centralized key management where trusted certificate authority (CA) provides public key certificate to mobile nodes in order to develop mutual trust between them. Any disturbance with CA can easily affect the security of the entire network.