IOSR Journal of Engineering
The concept of concealing the meaning of a message from all but the intended recipients is the job of a crypto system. The development of digital computers allowed the complexity of encryption algorithms to increase and to be used in a wide range of applications, including civilian use. This paper presents the construction of asymmetric and symmetric substitution boxes using an analytical approach. The objective was to generate S-Boxes that meet the Strict Avalanche Criteria (SAC), are non-linear, and have a high degree of resistance to differential cryptanalysis. It was found that it is possible to produce S-Boxes which exhibit robustness up to 0.96, and several were found to give above 70% compliance with the SAC.