RC4 Stream Cipher with a Random Initial State

Abstract

Rivest Cipher 4 (RC4) is one of the modern encryption techniques utilized in many real time security applications; however, it has several weaknesses including a correlation problem in the initially generated key sequences. In this paper, we propose RC4 stream cipher with a random initial state (RRC4) to solve the RC4's correlation problem between the public known outputs of the internal state. RRC4 solves the weak keys problem of the RC4 using random initialization of internal state S. Experimental results show that the output streams generated by RRC4 are more random than that generated by RC4. Moreover, RRC4's high resistivity protects against many attacks vulnerable to RC4 and solves several weaknesses of RC4 such as predictable first bytes of intermediate outputs by RC4. © 2013 Springer Science+Business Media Dordrecht.