1. Boot your system with a backtrack 5 live dvd ora pendrive.
2. Goto Backtrack > Exploitation Tools > Wireless Exploitation Tools > WLAN Exploitation > fern-wifi-cracker
3. This is will open a fern wifi cracker window. Now the First step is to select the interface. Here in my case i have selected wlan0 interface .
4. To scan for Access Point click on the 2nd button ( wifi icon ).
Once you get the Access Point ,various AP’s of WEP and WPA are detected.
Fern wifi cracking
Now I am going to crack the WEP Encryption .
In my case , i have selected one Access Point and click on the Attack button.
Access Points fern wifi cracking
Once you click on the Attack button , it will start collecting packets.
attack collect packer
WEP KEY FOUND
Once your IVS Packet count reaches 10000 or greater than that , its automatically crack the key and display it on the screen .
To see the database , click on the Key Database button .
WPA CRACKING : For WPA cracking the steps are same except you just need to specify the dictionary file (a file containing list of passwords) for the attack.