Corinex Global ADSL2+ - Manual (Page 118)

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Appendices
Corinex ADSL2+ Wireless Gateway G
Appendix B Wireless Security
A Brief Overview
Whenever data - in the form of files, emails, or messages - is transmitted over
your wireless network, it is open to attacks. Wireless networking is inherently risky
because it broadcasts information on radio waves. Just like signals from your cellular
or cordless phone can be intercepted, signals from your wireless network can also
be compromised. What are the risks inherent in wireless networking? Read on.
What Are The Risks?
Computer network hacking is nothing new. With the advent of wireless
networking, hackers use methods both old and new to do everything from
stealing your bandwidth to stealing your data. There are many ways this is done,
some simple, some complex. As a wireless user, you should be aware of the many
ways they do this.
Every time a wireless transmission is broadcast, signals are sent out from your wire-
less PC or access point, but not always directly to its destination. The receiving PC
or access point can hear the signal because it is within that radius. Just as with a
cordless phone, cellular phone, or any kind of radio device, anyone else within that
radius, who has their device set to the same channel or bandwidth can also receive
those transmission.
Wireless networks are easy to find. Hackers know that, in order to join a wireless
network, your wireless PC will typically first listen for “beacon messages”. These
are identifying packets transmitted from the wireless network to announce its pres-
ence to wireless nodes looking to connect. These beacon frames are unencrypted
and contain much of the network’s information, such as the network’s SSID (Serv-
ice Set Identifier) and the IP address of the network PC or access point. The SSID
is analogous to the network’s name. With this information broadcast to anyone
within range, hackers are often provided with just the information they need to
access that network.
One result of this, seen in many large cities and business districts, is called “War-
chalking”. This is the term used for hackers looking to access free bandwidth and
free Internet access through your wireless network. The marks they chalk into the
city streets are well documented in the Internet and communicate exactly where
available wireless bandwidth is located for the taking.