What is WiFi?
WiFi (or Wi-Fi) stands for wireless fidelity and is a term used to describe wireless local area networks (WLAN) technology .
WiFi adheres to the IEEE 802.11 standard (Institute of Electrical and Electronics Engineers) .
With WiFi-enabled devices (such as a laptop) one can connect to wireless router much as they would a regular router and
gain access to the Internet but without having to connect a physical wire to the laptop (i.e. - Ethernet cable).
Instead of using wires to transmit data WiFi-enabled devices send radio waves like a cell phone to communicate with one
another . As WiFi technology is continually improved the range of wireless
communication has extended from about 90 meters (300 feet) to 180 meters (600 feet) and it is still being improved .
WiFi has become so popular that it is not only used from within local coffee shops, hotels, or airports,
but entire cities (such as San Francisco, Portland, and Philadelphia ) are becoming WiFi-enabled,
thereby allowing virtually anyone within the city limits to gain wireless access.
The IEEE 802.11 networking standards are currently comprised of;
802.11b: the first version to be released that transmits in the 2.4 GHz
frequency, handling up to 11 Mbps.
802.11g: transmits at 2.4 GHz, handling up to 54 Mbps.
802.11a: transmits at 5.0 GHz, handling up to 54 Mbps.
More standards are currently being developed as the technology for wireless
communication advances. Such an example is 802.11n which is not yet released
but is anticipated to be faster than 802.11g [ 1].
WiFi, as a trademark is owned by a trade group called WiFi Alliance, an organization that now ensures
WiFi equipment complies with the IEEE 802.11x standards. The wireless
technology was branded under the name of WiFi in 1999 by the Wireless Ethernet Compatibility Alliance (WECA)
formed by the pioneering companies; 3Com, Cisco, Intersil, Agere, Nokia and Symbol Technologies. The WECA
was later renamed in 2003 as the WiFi Alliance .
Due to WiFi's growing popularity and availability hackers have turned their attention to invading
unsuspecting users and their laptops, stealing private information such as emails, login information for unsecured sites (non-SSL),
and even what websites they are viewing. Furthermore, via wireless connections hackers can actually hi-jack someone
else's Internet connection to send or recieve illegal information .
A technique known as Wi-Fi eavesdropping can be used by malicious users to see what packets are
being transmitted through the network. Packets that may contain the content of an email just sent, or
even the login name and password for the email server. All this information can be extracted by
any hacker within proximity of the user's wireless network that is sniffing for transmitted packets
Hackers have even been know to create lookalike networks which are networks with Service Set Identifiers (SSIDs)
that resemble typical hotpots (such as "linksys", "dlink", "tmobile", etc). Unsuspecting users log on to these networks assuming
that they are the public hotspots or their own network and although they have an Internet connection the hackers behind
the scenes are recording all of their private information [5, 6].
Currently the main methods to secure a private wireless network are;
Wired Equivalency Privacy (WEP): encryption scheme that can use 64-bit
or 128-bit, all network users must supply a numerical password to gain access .
WiFi Protected Access (WPA): more robust than WEP and is currently part
of the 802.11i security protocol. WPA is another encryption method and like WEP
requires all users to supply a password .
Media Access Control (MAC): unlike the previous two, this method only
allows computers with a physical address that is on the approved list to
connect to the network. No password is required as each computer has its' own
unique physical address .
Security countermeasures for public wireless networks are;
Using a Virtual Private Network (VPN) Connection .
Not sending any private information on non-SSL (Secure Sockets Layer) websites
Disabling all file sharing settings .
Using a personal firewall .
Brain, Marshall and Wilson, Tracy. "How WiFi
Howstuffworks.com. Last accessed March
30, 2007 from < http://www.howstuffworks.com/wireless-network.htm>
Anissimov, Michael. "What is WiFi?"
wiseGeek.com. Last accessed March 30,
2007 from < http://www.wisegeek.com/what-is-wifi.htm>
Wikipedia. Last accessed March 30, 2007
from < http://en.wikipedia.org/wiki/Wifi
Geier, Eric. "Wi-Fi Security Issues Up Close"
Wi-Fi Planet. Last accessed March 30,
2007 from <http://www.wi-fiplanet.com/tutorials/article.php/3605601>
Abdollah, Tami. "Ensnared on the wireless Web."
latimes.com. Last accessed March 30,
2007 from <http://www.latimes.com/news/local/la-me-wifihack16mar16,0,4434812,full.story?coll=la-home-headlines
Null, Christopher. "Beware the 'Evil Twin' Wi-Fi Hotspot."
tech.yahoo.com. Last accessed March 30,
2007 from <http://tech.yahoo.com/blogs/null/23163/beware-the-evil-twin-wi-fi-hotspot
Written by David Hwang. Last revision on April 05, 2007.