Improvement of chopchop attack

Abstract

Wired equivalent privacy (WEP) is a security protocol in the IEEE 802.11 wireless standard. At present, three attacks are frequently exploited: chopchop attack, Korek attack, and PTW attack. The first can decrypt a packet, while the latter two could recover user's key from known plaintext/ciphertext pairs. We propose more efficient combinational mode of these attacks, and also improve chopchop attack. Our chopchop version does not need to recover the integrity check value (ICV), which reduces 32 data frames forgery. Counting in case of data payload with average length 1,156 bytes, our combinational mode "chopchop + PTW" saves 1,141 bytes plaintext recovery, improving efficiency by 98 %. Furthermore, the mode "chopchop + Korek + PTW" saves 1,154 bytes plaintext recovery, receiving 99 % efficiency improvement. Meanwhile, our attack modes greatly reduce the risk of being detected. So it is more suitable for the real environment, especially when there is no client or low data communication. © 2013 Springer-Verlag.