Constructing key dependent dynamic S-Box for AES block cipher system

As the rapid evolution of digital data transaction in E-way is expanding, information safety is emerging with much more importance in data storage and broadcast. Cryptography has emerged as a significant solution which portrays a vivacious role in securing the information against several attacks. Advanced Encryption Standard block cipher (Known as AES) is an extensively studied and widely used cryptographic block cipher system to secure data and information. The strength of AES algorithm is determined by the choice of S-Box along with other aspects. This paper proposes a new technique to generate S-Box dynamically which will intensify the complexity of S-Box construction to encounter any possible attack on the fixed S-Box. Predefined static S-Boxes pose a weak point for the attackers to analyze certain cipher text pairs. The new S-boxes created are additionally dynamic, random and key dependent which attempts to escalate the complexity of the algorithm and furthermore mark the cryptanalysis more challenging. This paper discusses the importance of substitution S-boxes, their role in ensuring the strength of a cipher system and finally describes a new approach of generating dynamic S-box which is constructed centered on round key.