A New Variant of RC4 Stream Cipher

RC4 was used as an encryption algorithm in WEP(Wired Equivalent Privacy) protocol that is a standardized for 802.11 wireless network. A few attacks followed, indicating certain weakness in the design. In this paper, the authors proposed a new variant of RC4 stream cipher. The new version of the cipher does not only appear to be more secure, but its keystream also has large period, large complexity and good statistical properties. In cryptography, Substitution box (S-box) constitutes a cornerstone component of symmetric key algorithm that maps input vectors non-linearly into output vectors. It is used in both block ciphers and stream ciphers. In modern software efficient stream cipher, RC4 is one of the most widely used stream ciphers based on S-box.