Airlink security

Airlink security
The area that we really want to focus on in this chapter is the aspect of network
security that’s unique to wireless networks: the airlink security. In other
words, these are the security concerns that have to do with the radio frequencies
being beamed around your wireless home network.
Traditionally, computer networks use wires that go from point to point in
your home (or in an office). When you’ve got a wired network, you’ve got
physical control over these wires. You install them, and you know where they
go. The physical connections to a wired LAN are inside your house. You can
lock the doors and windows and keep someone else from gaining access to
the network. Of course, you’ve got to keep people from accessing the network
over the Internet, as we mention in the previous section, but locally it would
take an act of breaking and entering by a bad guy to get on your network.
(Sort of like on Alias where they always seem to have to go deep into the
enemy’s facility to tap into anything.)
Wireless LANs turn this premise on its head because you’ve got absolutely no
way of physically securing your network. Now you can do things like go outside
with a laptop computer and have someone move the access point around
to reduce the amount of signal leaving the house. But that’s really not going
to be 100 percent effective, and it can reduce your coverage within the house.
Or you could join the tinfoil hat brigade (“The CIA is reading my mind!”) and
surround your entire house with a Faraday cage. (Remember those from
physics class? Us neither, but they have something to do with attenuating
electromagnetic fields.)
Some access points have controls that let you limit the amount of power
used to send radio waves over the air. This isn’t a perfect solution (and it can
dramatically reduce your reception in distant parts of the house), but if you
live in a small apartment and are worried about beaming your Wi-Fi signals to
the apartment next door, you might try this.
Basically, what we’re saying here is that the radio waves sent by your wireless
LAN gear are going to leave your house, and there’s not a darned thing
that you can do about it. Nothing. What you can do, however, is make it difficult
for other people to tune into those radio signals, thus (and more importantly)
making it difficult for those who can tune into them to decode them
and use them to get onto your network (without your authorization) or to
scrutinize your e-mail, Web surfing habits, and so on.
You can take several steps to make your wireless network more secure and to
provide some airlink security on your network. We talk about these in the following
sections, and then we discuss some even better methods of securing
wireless LANs that are coming down the pike.