Reducing the State Space of RC4 Stream Cipher

Abstract

Abstract. The paper introduces an abstraction in form of general conditions for cryptanalytic managing of the information about the current state of the RC4 stream cipher. The general conditions based strategy is used to favor more promising values that should be assigned to unknown entries in the RC4 table. The estimated complexity of the cryptanalytic attack is lower than the best published result although the RC4 remains a quite secure cipher in practice.

An approach of refining RC4 with performance analysis on new variants

“…Nawaz et al [10] introduced a new 32-bit RC4-like faster key-stream generator with a huge internal state and offered higher resistance against state recovery attacks. Tomašević and Bojanić [11] proposed a new technique to improve cryptanalytic attack on RC4 based on a tree representation of RC4. The strategy has been used to favour more promising values that should be assigned to unknown entries in the RC4 table.…”