WEP isn't as safe as you might think. Even 128 bit WEP isn't safer than 64 bit WEP. The Achille's heal is the 24 bit IV (initialization vector.) Hackers will go after that to gain access to your wireless network. There are known tools out there easily found on the internet which will allow anyone proficient in hacking wireless networks to break any WEP encryption in a matter of 10-15 minutes.
WPA also has some vulnerabilities. I forget where I read the method of hacking WPA but it's definitely possible. WPA is still pretty secure but to eliminate the remote chance of anyone trying to penetrate your network, changing the SSID periodically will give hackers fits.
from tom's guide.
do you really think someone is going to take the time to access my wep, i don't.
2. What you Need
Although WEP cracking can be done from a single laptop, ideally you should have two. One laptop performs an active attack to stimulate data flow so that a sufficient number of packets can be captured in a relatively short amount of time, while the other laptop "sniffs" or captures the traffic produced by the attacking laptop. Figure 2 shows the basic idea.
You can actually run a WEP crack using one notebook equipped with a single wireless LAN card, but we don't recommend this configuration as a starting point. With only one notebook, its easy to get confused about what you're doing and we've found that the Auditor programs can get a bit unstable when used in this way.
Figure 2: Two Notebook WEP cracking setup
Note that using an active attack vs. passively capturing traffic increases your chances of detection. But it can significantly speed a WEP key crack by forcing the generation of more packets than you would normally capture in a short time from a lightly-used WLAN.
Tip: Although we refer to laptops / notebooks throughout this series, you can also use desktop computers or a mixture of laptops and desktops. However, you may find using notebooks easier due their portability and the wider range of compatible PC Card wireless adapters available.
Here is a list of required hardware:
Wireless Access Point - This will be the "target" access point and can be any brand. We used a Netgear WGT624 v2
A laptop or computer with wireless capability - This will be the "target" computer and it doesn't matter which wireless chipset or card the computer uses. Our lab had a surplus Dell laptop with built-in wireless that worked just fine
Two 802.11b PC Cards based on the PRISM 2 chipset - Some of the programs (such as Kismet) we use in this series can support a wide variety of wireless cards. But we suggest you stick to using cards based on the PRISM 2 chipset, which are supported by all the programs we will use.
We used two 2511CD PLUS EXT2 cards. The 2511-CD PLUS EXT2 has two MMCX connectors for external antennas and does not have an internal antenna.These cards are typically found under the Senao, Engenius or Wireless LAN brand names (Figure 3).
You can also search this list compiled by Absolute Value Systems to find other PRISM 2-based cards.
Figure 3: Senao 2511 802.11 PC Card
Tip: We bought most of our wireless gear (cards, antennas, pigtails) from wlanparts.com.