In the upcoming parts of this chapter, we're going to discuss Wi-Fi Protected Access (WPA) encryption. This encryption was designed after WEP, to address all of the issues that made WEP very easy to crack. The main issue with WEP is the short IV, which is sent in each packet as plain text. The short IV means that the possibility of having a unique IV in each packet can be exhausted in active networks, so that when we are injecting packets (or in natural, active networks), we will end up with more than one packet that has the same IV. When it happens, aircrack-ng can use statistical attacks to determine the key stream and the WEP key for the network.

In WPA, however, each packet is encrypted using a unique, temporary key. It means that the number of data packets that we collect is irrelevant; even if we are able to collect one million packets, these packets are not useful, because they do not contain any information that can help us crack the WPA key. WPA2 is the same; it works with the same method, and it can be cracked using the same method. The only difference between WPA and WPA2 is that WPA2 uses an algorithm called Counter-Mode Cipher Block Chaining Message Authentication Code Protocol (CCMP) for encryption.