The Essentials of Wireless Security

Typically ‘normal’ users of products such as wireless routers dismiss any security concerns as only really being applicable to commercial concerns. After all, who would be interested in a small local set-up of two, maybe three computers? You may be surprised. There are many horror stories circulating about unsecured wireless networks, and unfortunately there is a grain of truth in most of them.

The most common form that a danger to a private network can take is known as variously as ‘War-driving’, ‘war-walking’, ‘war-flying’ or ‘war-chalking.’ This involves an unscrupulous person literally driving, walking or even flying around in an attempt to find an unsecured wireless network. Once one is found a nearby wall is commonly ‘chalked’, indicating to any other passer-by the presence of a ripe target. The name itself is taken from the act of ‘war-dialling’, a term coined by the film ‘WarGames’, where random telephone numbers were dialled in the hope of finding a computer on the other end of the line.

If a network is found, then the potentialconsequences can range from the fairly innocuous to the criminal. At the very lowest level a third-party can connect to the network and access the Internet connection from the router. If the legitimate owner of the network is on a capped service this can consume a considerable chunk of their bandwidth, leading to extra charges being levied for resources which they never realised were being used. Of far more consequence are some of the uses to which this stolen bandwidth could be put. In a worst case example a paedophile cruising around the area could spot the chalk marking and connect to the compromised network. Without the knowledge of the network owners they could connect to any manner of illegal sites, with no record of their passing traceable to them. Because the trail would stop cold at the door of the person who has provided them with the free access.

Of course this is a very worst-case example, and as such very unlikely. Even in today’s climate of moral decrepitude this sort of occurrence would, we hope, be extraordinarily rare. But hopefully it will help drive home the point that securing your network should be taken very seriously indeed. But what can you do to protect yourself?I would recommend that all wireless networks should make use of the WEP (Wired Equivalent Privacy) encryption option which comes as standard with almost all routers and base stations. Although turned off by default this feature is absolutely essential. Utilising either 64-bit encryption, which creates a 64bit encryption based on a 40-bit key with a 24-bit initialisation vector, or 128-bit encryption which makes use of a 104-bit key with a 24-bit initialisation vector, a secure password is created. This password should only be given to known and trusted wireless devices, blocking access to any interloper. This, although not secure against dedicated crackers, provides a more than adequate protection to dissuade the nosy or the vast majority of war-drivers.

Too few people enable this basic protection, or are even aware it exists. However in some regards protecting your network can be as essential as your childhood inoculation against tetanus. So please, take just a few minutes of your time to configure your WEP encryption, and to help protect yourself.

For a more in-depth technical overview of the points covered in this article you can visit http://www.iss.net/wireless/WLAN_FAQ.php, a very useful, if slightly esoteric, overview of various security concerns over the standard 802.11 wireless specification.