Improved Dynamic S-Box generation using Hash function for AES and its Performance Analysis

Abstract

With the development of information technology and increasing demands for information security, various encryption methods have been attracted more and more attention in recent years. AES is one such symmetric key algorithm used for securing the data that transmits in the Internet. The strength of AES block cipher depends on the S-Box structure which is a nonlinear substitution operation. S-Boxes are fundamental component of symmetric key algorithms which performs substitution. Since the Substitution boxes are dynamically created, this fact makes it clear that both linear and differential cryptanalysis cannot be done on Dynamic S-Boxes. They are basically used in block ciphers to make the affiliation between key and cipher text more unfamiliar. There are lots of techniques used for generation of S-Box such as key dependent S-Box in which S-Box depends on the key, Bijection, Strict Avalanche criterion etc. This paper briefly analyzes the structure of AES algorithm and a dynamic S-Box is generated based on hash function. Also, the eminence of generated S-Box is been experimentally evaluated and compared along with the original AES for the simulation time.