Performance Comparison of Advanced Encryption Standard (AES) and AES Key Dependent S-Box - Simulation Using MATLAB

The growing popularity of mobile and hand held devices ignited the growth of wireless networks over the past years. Wireless data communications have transformed not only the business world but also the human society by improving efficiency, flexibility, convenience, and above all productivity. Wireless Local Area Networks (WLAN) typically emulate the wired networks traditional hub-spoke configuration. The best known and most widely used variation of the 802.11 WLAN standard is 802.11b. Encryption in 802.11b is provided by Wired Equivalent Privacy (WEP), which has many weaknesses and flaws. Therefore the IEEE ratified 802.11i WLAN security standard in June 2004. The new cryptography was based on the Advanced Encryption Standard (AES) algorithm. The Substitution box (S-box) in AES brings non linearity to cryptosystem and strengthens their cryptographic security. In this paper RC4 stream cipher is used to generate S-box for AES. The generated S-boxes are more dynamic and key dependent which will increase the complexity and make the differential and linear cryptanalysis more difficult.