Performance analysis of modified RC4 encryption algorithm

RC4 is one of the most widely accepted stream cipher on account of its structural simplicity, encryption and decryption speed and efficiency. In this paper, we report on several vulnerabilities of RC4 algorithm and further propose a modified RC4 (MRC4) algorithm to overcome the weaknesses of RC4. Working of RC4 consists of two parts: key scheduling algorithm (KSA) and pseudo random number generator algorithm (PRGA). In MRC4, additional layers are added to both KSA and PRGA without modifying its basic structure. Performance analysis of the conventional RC4 algorithm and its proposed variant has been performed in terms of running time, security, and randomness analysis. Through numerical results it is shown that while retaining the simplicity of RC4, MRC4 enhances the security of the stream cipher.