- slide 1 of 8
In 1997, the Institute of Electrical and Electronics Engineers (IEEE), a widely-known and influential organization when it comes to computer networking, developed a standard of wireless networking called 802.11. It was a modification of the original networking standard, 802.3, more commonly known as Ethernet, or what you might know as a common Internet cable. 802.11, instead of using a cable, specifies an over-the-air interface between a wireless client (such as a laptop) and a base station (like a router), or between two wireless clients1. Over the years, the IEEE has adapted the 802.11 standard to users’ needs.
- 802.11a was the first revision, operating at a higher bandwidth than the original standard (5 GHz). It has a maximum throughput (transfer rate) of 54 Mbps (megabits per second), though realistically it usually peaks at about 20 Mbps. The advantage of this revision is that the bandwidth at which it operates is less frequently used than the lower range of 2.4 GHz that was originally utilized – which suffered from interference from such things as microwaves, cordless phones, baby monitors, and some FM radio devices. The major disadvantage of this revision, however, was that at the higher bandwidth, the radio waves were more readily absorbed by any interference, like walls, which reduced the range.
- 802.11b was the next revision of the 802.11 standard. This revision fell back to the 2.4 GHz bandwidth, allowing for greater range due to its ability to penetrate solid objects more easily. It was much slower than 802.11a, however, with a maximum throughput of 11 Mbps (averaging between 2 and 5.5 Mbps realistically). Like the original standard, it also suffered from radio and microwave interference, but it is less noticeable than it was when 802.11 was originally created.
- 802.11g followed 802.11b in approximately 2003. Combining the best of both worlds, the 802.11g revision offered a maximum throughput of 54 Mbps with the greatly increased range that the 2.4 GHz bandwidth offered. It suffers from the same problems today as its predecessor, however.
- 802.11n is the newest revision standard approved by the IEEE. It operates in both the 2.4 and 5 GHz bands, and uses multiple antennas to send and receive data. The realistic speed of 802.11n is approximately 100 Mbps, making it five times faster than its predecessors.
In addition to the different types of wireless signal (defined above), it is also important to know some of the basic concepts of wireless security. Let's have a look at them below.
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Open System Authentication
Open system authentication is the equivalent of having no security on your wireless-enabled router at all. It allows anyone who can locate your network to connect to it, without verifying if that device should be allowed onto your local network or not. It is highly recommended to avoid open system authentication if at all possible on home wireless networks.
- slide 3 of 8
There are three main types of router security. The least secure of these is Wired Equivalent Privacy (WEP). It is certainly better than nothing, but internet crackers have proven that the security of WEP, which uses a simplistic encryption algorithm to encode data, can be broken in three minutes using publicly available tools2. In addition, all devices in the local area network (LAN) – in other words, all the devices connected to your router – share one password to access the network. If an attacker gets the password to access the network on one computer, they can access all of the computers on the network.
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The next best protocol to use to secure your router is Wi-Fi Protected Access version 1 (WPAv1). It uses an 8 to 64 character pre-shared key (PSK) to establish security. Some routers list this as WPA-PSK or WPA-TKIP (with TKIP being the specific encryption protocol used). TKIP then takes the password sent by the client device (your laptop, for example) and encrypts it before sending it across to the base unit – your router – which then decrypts the password and verifies that it matches what it has as the password. Once this has been verified, the client device is authorized to connect to the base unit. The use of a PSK creates a vulnerability in the protocol, because (like WEP) an attacker only has to discover the password once to get access to all the computers on the LAN. WPA has an advantage over WEP, though, because it can use encryption to pass the PSK over the wireless connection (usually TKIP or, less commonly, AES).
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The third and most secure wireless security protocol in common use is WPAv2. It is similar to WPAv1, except that it generally uses an encryption protocol called AES (and some routers list this as WPA2-AES or WPA2-PSK). It utilizes the concept of a Robust Security Network (RSN), which requires wireless devices to support older protocols such as WEP3.
- slide 6 of 8
TKIP and AES
Temporal Key Integrity Protocol (TKIP), defined in the IEEE 802.11i standard, addresses encryption. When it was designed, it had to be backward-compatible with older equipment that only supported WEP. It solved a lot of the problems with basic WEP, because it changes the key used for each packet of data sent over the wireless network4. However, like WEP, it uses a password that has to be known by everyone on the wireless LAN.
Advanced Encryption Standard (AES) was designed as a replacement for a very strong, but resource-heavy, encryption protocol called 3DES (Triple Data Encryption Standard). It breaks the data to be encrypted into 128-bit blocks and encrypts them a certain number of times dependent on the version of AES that is being used.
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Some of the more common terms, such as 802.11a/b/g/n, WEP, WPA, and encryption protocols like TKIP and AES are not easy to understand unless you come across them and use them frequently. It’s a good idea to get a basic working knowledge of these terms in today’s world, though, so that when you set up your home network, you have a better understanding of which protocols and levels of security are right for you.
- slide 8 of 8
 Brinkmann, Martin. “Cracking WEP the FBI way", http://www.ghacks.net/2006/07/02/cracking-wep-the-fbi-way/
 dlaverty. “WPA vs WPA2 (802.11i): How your Choice Affects your Wireless Network Security", http://www.openxtra.co.uk/articles/wpa-vs-80211i
 Snyder, Joel, and Rodney Thayer. “Explaining TKIP", http://www.networkworld.com/reviews/2004/1004wirelesstkip.html
Screenshots courtesy of author.