Performance Analysis of LDPC Decoding Techniques Enhancing Hierocrypt-3 performance by modifying its S-Box and modes of operations Different Types of Attacks on Block Ciphers Performance Analysis of Advanced Encryption Standard (AES) S-boxes Algebraic Construction of Powerful Substitution Box Appraisal of Multiple AES Modes Behavior using Traditional and Enhanced Substitution Boxes Comparative Study of Algebraic Attacks Algebraic Cryptanalysis of AES using Gröbner Basis