A new form of initialization vectors in the FMS attack of RC4 in WEP

Abstract

Abstract S. Fluhrer, I. Mantin and A. Shamir (FMS) had put forward a fascinating attack of the key of RC4 in Wired Equivalent Privacy (WEP) protocol on the basis of special initialization vectors (IVs) of pattern (3, 255, v). Inspired by the FMS attack, this paper tries to find new pattern of IVs that can be used for recovering the key of RC4 in WEP. We discovered that IVs of new pattern (v, 257-v, 255) can also be used in the FMS attack in a very similar way. Combining the new pattern with the previous pattern (3, 255, v) could result in a higher proportion of IVs that can be exploited in the FMS attack.