A firewallis a piece of hardware or a software program that sits — in reality
or in logic form — between your machine and the outside world. In a wired
environment, the firewall may exist in the router that connects a single
machine to others or the entire network to an incoming broadband Internet
service. As a piece of software, a firewall is constantly on the lookout for any
activity not specifically authorized by the user or that is suspicious, like an
inward reach for data not initiated by your actions.An antivirusis a second line of defense. A good program performs a number
of actions, including scanning all incoming (and outgoing) e-mail for mali-
cious code as well as keeping an eye on the microprocessor for unusual
functions. Those functions range from requests to alter the hard drive’s
boot tracks to unsolicited probes of the drive’s contents. (Chapter 7 details
hard drives.)This is another reason to update your machine to use the latest WiFi standard;
at the time of publication that is 802.11g. This standard, though not perfect,
includes improved security elements called WiFi Protected Access (WPA).
This replaces the earlier (a and b) scheme called Wired Equivalent Privacy
(WEP), which was not all that private.Keep your operating system up to date. Microsoft and Apple are constantly
adding patches, fixes, and new features. If you’re using Windows XP, it defi-
nitely makes sense to upgrade to Windows XP Service Pack 2 to take advantage
of new and improved facilities.And then keep an eye on the developing later standards. The coming 802.11i
version is supposed to include a new security method called Temporal Key
Integrity Protocol, which will build an even higher and tougher wall between
your machine and hackers.To this I add one more suggestion: Always conduct your business as if you
assume that someone is out there trying to steal your secrets. If you are in a
strange location, like a coffee shop or hotel, try to avoid doing your banking
or managing your portfolio. If you absolutely must do so, regularly change
your password for these accounts and keep a close eye on balances and
transactions for any activity you did not authorize. Your e-mail account is
probably of little interest to a hacker, but nevertheless you should regularly
change the password.And finally, while you are working, keep an eye on your screen and its indica-
tor lights; also keep an ear tuned to the sounds of your hard drive. If you see
or hear something unusual when you are going wireless — something that
is different from what you see or hear when your machine is attached to an
Ethernet cable — sign off the WiFi connection andshut off or remove the WiFi
adapter.212 Part IV: Failing to Communicate