How To Crack A Wi-Fi Network’s WEP Password

You already know that if you want to lock down your Wi-Fi network, you should opt for WPA encryption because WEP is easy to crack. But did you know how easy? 

What you will need

A compatible wireless adaptor

A BackTrack 3 Live CD

A nearby WEP-enabled Wi-Fi network

Patience with the command line

Crack that WEP

To crack WEP, you’ll need to launch Konsole, BackTrack’s built-in command line. It’s right there on the taskbar in the lower left corner, second button to the right. Now, the commands.

First run the following to get a list of your network interfaces:

airmon-ng

The only one I’ve got there is labelled ra0. Yours may be different; take note of the label and write it down. From here on in, substitute it in everywhere a command includes (interface).

Now, run the following four commands. See the output that I got for them in the screenshot below.

airmon-ng stop (interface)

ifconfig (interface) down

macchanger –mac 00:11:22:33:44:55 (interface)

airmon-ng start (interface)

If you don’t get the same results from these commands as pictured here, most likely your network adaptor won’t work with this particular crack. If you do, you’ve successfully “faked” a new MAC address on your network interface, 00:11:22:33:44:55.

Now it’s time to pick your network. Run:

airodump-ng (interface)

To see a list of wireless networks around you. When you see the one you want, hit Ctrl+C to stop the list. Highlight the row pertaining to the network of interest, and take note of two things: its BSSID and its channel (in the column labelled CH), as pictured below. Obviously the network you want to crack should have WEP encryption (in the ENC) column, not WPA or anything else.

Like I said, hit Ctrl+C to stop this listing. (I had to do this once or twice to find the network I was looking for.) Once you’ve got it, highlight the BSSID and copy it to your clipboard for reuse in the upcoming commands.

Now we’re going to watch what’s going on with that network you chose and capture that information to a file. Run:

airodump-ng -c (channel) -w (file name) –bssid (bssid) (interface)

Where (channel) is your network's channel, and (bssid) is the BSSID you just copied to clipboard. You can use the Shift+Insert key combination to paste it into the command. Enter anything descriptive for (file name). I chose "yoyo", which is the name of the network name I'm cracking.

You'll get output like what's in the window in the background pictured below. Leave that one be. Open a new Konsole window in the foreground, and enter this command:

aireplay-ng -1 0 -a (bssid) -h 00:11:22:33:44:55 -e (essid) (interface)

Here the ESSID is the access point’s SSID name, which in my case is yoyo. What you want to get after this command is the reassuring “Association successful” message with that smiley face.

aireplay-ng -3 -b (bssid) -h 00:11:22:33:44:55 (interface)

Here we’re creating router traffic to capture more throughput faster to speed up our crack. After a few minutes, that front window will start going crazy with read/write packets. (Also, I was unable to surf the web with the yoyo network on a separate computer while this was going on.) Here’s the part where you might have to grab yourself a cup of coffee or take a walk. Basically you want to wait until enough data has been collected to run your crack. Watch the number in the “#Data” column—you want it to go above 10,000. (Pictured below it’s only at 854.)

Depending on the power of your network (mine is inexplicably low at -32 in that screenshot, even though the yoyo AP was in the same room as my adaptor), this process could take some time. Wait until that #Data goes over 10k, though—because the crack won’t work if it doesn’t. In fact, you may need more than 10k, though that seems to be a working threshold for many.

nce you’ve collected enough data, it’s the moment of truth. Launch a third Konsole window and run the following to crack that data you’ve collected:

aircrack-ng -b (bssid) (file name-01.cap)

Here the filename should be whatever you entered above for (file name). You can browse to your Home directory to see it; it’s the one with .cap as the extension.

If you didn’t get enough data, aircrack will fail and tell you to try again with more. If it succeeds, it will look like this:

The WEP key appears next to “KEY FOUND.” Drop the colons and enter it to log onto the network.

Wifi Network

What is a WiFi Network-How to Setup
An Introduction to the Wi-Fi (Wireless Fidelity)
Here you will learn how to setup wifi network, how wireless fidelity works, hotspot security, vpn servers. Wi-Fi or wireless fidelity is meant for to be used when referring any type of 802.11 network, whether 802.11, 802.11a and dual band. Any products tested and approved as Wi-Fi certified by the Wi-Fi alliance are interoperable with each other.  

Typically, any Wi-Fi product using the same radio frequency will work with each other even if not Wi-Fi certified. Formerly the term Wi-Fi was used only in the place of the 2.4 GHz 802.11b standard in the same way Ethernet was used.

Wi-fi short for wireless fidelity refers to a set of wireless networking technologies and more specifically referred to as any type of 802.11 network, 802.11b and 802.11a and dual band. The word Wi-Fi was built by an organization named as Wi-Fi alliance. A product that undergoes the Wi-Fi alliance analyses is given the name Wi-Fi certified.


Wi-Fi rapidly gained the fame in the United States with the access point. These devices tested by the “Wi-Fi alliance” are used around the world and allow users to have Wi-Fi capable device like a PDA or Laptop to connect anywhere there is availability of Wi-Fi access point. There are currently three standards that are used to signify the speed of the connection. Both the 802.11a and 802.11b are the capable of 54 Mbps with 802.11a additional features. The most common standard is 802.11b/second because it can transmit the data at 11 Mbps.



All these Wi-Fi connections are fast enough to allow the broadband internet connection. Wireless Fidelity is a fastest growing wireless technology that will probably be as common as phone lines and electric devices. Wi-Fi adds great levels of convenience and high level of production.
Wireless fidelity is planned to be used with the wireless devices but it is most commonly used for internet access. With Wi-Fi you can connect computers in your home, office or anywhere without the need of wires. The computers can just connect to the network that uses radio waves.


How does W-Fi work?
Wi-Fi is the wireless technology to handle the networking/communication. Wi-Fi allocates internet connection globally and to be transmitted by the radio waves. Radio waves are the main cause of Wi-Fi. Radio waves are transmitted from antenna and Wi-Fi receivers pick them up. When a user receives the Wi-Fi signals, a wireless internet connection is produced and a user is prompted to provide the user name and password if required to establish a wireless connection.


Wi-Fi Hotspot Security: Using VPNs
There are numerous security issues regarding the use of the public wireless networks but all of which can be overcome. One of the solutions for users, as brought up in Wi-Fi Hotspot security, is to use the VPN (Virtual Private Network) to secure the real time traffic of the Wi-Fi hot spot users. Many small to large businesses provide their employees with the VPN access.
Although this access is typically put in place for employees to have the remote access to the corporate network in order to access the files and documents remotely. If you don’t have access to any VPN servers, create your own. By doing this you can remotely access the files from your office as well as other devices such as Wi-Fi video camera to keep an eye on the things while away.
When using the software-based VPN server features in Windows XP Pro, the PC running the server has to be powered-on to access the home network from the Wi-Fi hotspot. VPN routers can cost as low as $70 to $130 and the popular models are Linksys, WRV200 and WRV5G.

Basic Internet Technical Details

The Internet utilizes a set of networking protocols called TCP/IP. The applications
protocols that can be used with TCP/IP are described in a set of Internet
Engineering Task Force (IETF) RFCs (Request For Comment). These documents
describe the "standard" protocols and applications that have been developed to
support these protocols. Protocols provide a standard method for passing
messages. They define the message formats and how to handle error conditions.
Protocols are independent of vendor network hardware, this allows communication
between various networks with different hardware as long as they communicate
(understand) the same protocol. The following diagram provides a conceptual
layering diagram of the protocols.