AirSnort is a wireless LAN (WLAN) tool which recovers encryption keys.
AirSnort operates by passively monitoring transmissions, computing the
encryption key when enough packets have been gathered.
802.11b, using the Wired Equivalent Protocol (WEP), is crippled with numerous
security flaws. Most damning of these is the weakness described in " Weaknesses
in the Key Scheduling Algorithm of RC4 " by Scott Fluhrer, Itsik Mantin and Adi
Shamir. Adam Stubblefield was the first to implement this attack, but he has
not made his software public. AirSnort, along with WEPCrack, which was released
about the same time as AirSnort, are the first publicly available
implementaions of this attack.
AirSnort requires approximately 5-10 million encrypted packets to be gathered.
Once enough packets have been gathered, AirSnort can guess the encryption
password in under a second.