Wednesday, June 1, 2005

Secure transmissions in the mobile ad-hoc network

WIRELESS INFRASTRUCTURE

By Humayun Bakht

Computing and its advancement have brought dramatic changes in today's world. We feel its presence in almost all aspects of our daily life. Mobile ad-hoc, or instantaneous networks are one of the latest inventions in the family of wireless or cellular networks. The network is a short-lived, temporary network established by two or more mobile devices in the absence of fixed infrastructure.

Here, fixed infrastructure refers to different network devices, such as routers and base stations used in fixed wireless networks. Mobile ad-hoc networking is an advantageous way of exchanging peer-to-peer information among different types of network devices. The uses of this type of network is increasing dramatically and include business, entertainment, and safety applications. In this article I'll discuss various security-related requirements in a mobile ad-hoc network. I'll also suggest a possible solution to secure data transmission in these types of networks.

It would be a good idea to have a quick look at routers and base-stations. A router is a device that determines the next network point to which a data packet should be forwarded or routed toward its destination. On the other hand, a base station is the central radio transmitter, or receiver, that maintains communications with mobile radio-telephone sets within a given transmission range.

In mobile ad-hoc networks, there are no routers or base stations. Each participating node functions as a router, offering packet-forwarding services to all other nodes in the network. The only problem in gaining a successful routing mechanism in these types of networks is the development of a routing protocol that can cope with the typical nature of mobile ad-hoc networks.

In mobile ad-hoc networks, a mobile node meets two types of security challenges: import and export authorization. Import authorization requires a node acting as a router to decide weather or not it should modify its routing information when it receives information from somewhere outside. Export authorization requires the router to make a decision whenever it receives a request for routing information. Overall, the fundamental security challenges of mobile ad-hoc networks can be categorized as follows.

  • Import authorization: refers to the authority of routing messages regarding a certain destination node.
  • Source authentication: we need to be able to verify that the node is the one it claims to be.
  • Integrity: we need to be able to verify that the routing information that it is being sent to us has arrived safely.