Wireless Home Networking - Index of

Chapter 9: Securing Your Wireless Home Network
For most home users, this isn’t a problem (we don’t think that you have to
worry about giving Nana the passphrase for your network when she’s in town
visiting her grandkids), but in a busy network (such as in an office), where
people come and go (employees, clients, customers, and partners, for example),
you can end up in a situation where just too many people have your
shared secret.
When this happens, you’re stuck with the onerous task of changing the shared
secret and then making sure that everyone who needs to be on the network
has been updated. It’s a real pain.
These kinds of busy networks have authentication systems that control the
encryption keys for your network and authorize users on an individual basis
(so that you can allow or disallow anyone without having to start from
scratch for everyone, like you do with a shared secret).
If you have this kind of busy network, you may want to consider securing
your network with a system called WPA Enterprise and 802.1x. See the sidebar
“802.1x: The corporate solution” later in this chapter, for more information on
this topic.
Introducing Wired Equivalent
Privacy (WEP)
The original system for securing a wireless Wi-Fi network is known as WEP, or
Wired Equivalent Privacy. The name comes from the admirable (but, as we
discuss, not reached) goal of making a wireless network as secure as a
wired one.
In a WEP security system, you enter a key in the Wi-Fi client software on each
device connecting to your network. This key must match the key you establish
when you do the initial setup of your access point or wireless router
(which we describe in Chapter 7).
WEP uses an encryption protocol called RC4 to secure your data. Although
this protocol (or cipher) isn’t inherently bad, the way that it’s implemented in
WEP makes it relatively easy for a person to snoop around on your network
and figure out your key. And after the bad guys have your key, they can access
your network (getting into PCs and other devices attached to the network or
using your Internet connection for their own purposes) or stealthily intercept
everything sent across the wireless portion of your network and decode it
without your ever knowing!
It doesn’t take superhacker skills to do this either — anyone with a Windows
or Linux or Mac PC with wireless capabilities can download free and readily
available software from the Web and, in a short time, figure out your key.
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