Practical Attacks Against WEP and WPA
This paper describes two attacks on IEEE 802.11 based wireless LANs. The first attack is an improved key recovery attack on WEP, which reduces the average number of packets an attacker has to intercept to recover the secret key. The second attack is (According to the Knowledge) the first practical attack on WPA secured wireless networks, besides launching a dictionary attack when a weak Pre Shared Key (PSK) is used. The attack works if the network is using TKIP to encrypt the traffic. An attacker, who has about 12-15 minutes access to the network, is then able to decrypt an ARP request or response and send 7 packets with custom content to network.