Aircrack is a tool that can be used to crack 802.11 WEP and WPA-PSK keys, as well as perform some level of wireless network analysis. Aircrack was originally written by Christophe Devine and last released as version 2.41 on November 22, 2005. Since this version, the project was taken over and rereleased as Aircrack-ng. As of this book's printing, the latest version of Aircrack-ng was released October 1, 2006 as version 0.6.2. Despite the new code branch and the new name, many people continue to refer to the tool by the original name, Aircrack.
Aircrack uses two implementations: the FMS attack, which is named after the researchers who identified the weaknesses in WEP (Scott Fluhrer, Itsik Mantin, and Adi Shamir), and the much faster KoreK attack, which is a statistical cracking method that has proven to be more efficient than FMS attacks. From an attacker's perspective, the case for Aircrack is quite obvious. From a defense perspective, although Aircrack is useful for a number of tasks—such as testing current legitimate wireless networks to prove the need for better security implementations and identifying wireless networks in your organization—there are better tools that can be used for simply identifying a wireless network, as presented in Chapter 5.
Aircrack-ng is a suite that contains six different components, shown in Table 8-1.
Table 8-1. Aircrack-ng components