
This is the approach used to crack the WPA/WPA2 pre-shared key. There is another important difference between cracking WPA/WPA2 and WEP. So make sure airodump-ng shows the network as having the authentication type of PSK, otherwise, don't bother trying to crack it. aircrack-ng can ONLY crack pre-shared keys. WPA/WPA2 supports many types of authentication beyond pre-shared keys. The WPA Packet Capture Explained tutorial is a companion to this tutorial. This is the link to download the PDF directly. The best document describing WPA is Wi-Fi Security - WEP, WPA and WPA2. The Wiki links page has a WPA/WPA2 section.

I recommend you do some background reading to better understand what WPA/WPA2 is. This tutorial walks you through cracking WPA/WPA2 networks which use pre-shared keys.
