Possible Modifications of RC4 Stream Cipher

Abstract

In this paper, we consider possible modifications of the stream cipher RC4, which became widespread due to its properties, such as elegant design and an effective software and hardware implementation. We present an enhancement version of the RC4 algorithm, which obtained by adding parallel LFSR and stochastic transformation boxes (R-boxes). The result of proposed modification is the increased complexity of dependence between the key and the initial state of the cipher, as well as increased bit depth of the internal state.