An analytical review of current S-box design methodologies, performance evaluation criteria, and major challenges

The expansion of worldwide networking has created new possibilities for management, development, and presentation in the form of digital data. The uncomplicated accessibility to digital resources i.e., internet banking, electronic advertising, digital marketing, and libraries has resulted in grave security concerns. Consequently, rapid use of digital information and technology, security of digital transactions is a big concern. Although many data security solutions exist, still they need further improvement. In symmetric cryptography, the strength of a Substitution Box (S-box) assures the strength of block ciphers. S-box is a critical nonlinear element of cryptosystem that creates turmoil in transactions. This study aims to formulate a variety of methodologies to measure the effectiveness of an S-box against linear and differential algebraic attacks. These malicious attacks may disrupt and leak confidential information. Therefore, a comparative analysis is presented to understand the S-box construction methodologies, key characteristics of eminent S-boxes, major challenges, and their weak cryptographic properties. S-box is considered to be secure if it meets a number of criteria, i.e., maximum linear probability, bijection, nonlinearity, input/output XOR distribution, bit independence criterion, and strict avalanche criterion. These criteria are analyzed in detail to evaluate the performance, reliability, and effectiveness of S-box.