RC4 stream cipher and possible attacks on WEP

Abstract

In this paper we analyze and present some weaknesses and possible attacks on the RC4 stream cipher which were published in many journals. We review some advantages and disadvantages which come from several authors, as well as similarities and differences which can be observed in the published results. Also, we analyze the Key Scheduling Algorithm (KSA) which derives the initial state from a variable size key, and strengths and weaknesses of the RCS stream cipher. Using examples from other papers, we show that RC4 is completely insecure in a common mode of operation which is used in the widely deployed Wired Equivalent Privacy protocol (WEP, which is part of the 802.11 standard).