Extended SAC: A review and new algorithms of differential cryptanalysis of 4-bit s-boxes and strict avalanche criterion of BFs and 4-bit s-boxes again with a new extension to HO-SAC criterion

Bitwise-Xor of two 4 bit binary numbers or 4-bit bit patterns entitled 4-bit differences carries information in Cryptography. The Method to Analyze Cryptographic cipher algorithms or 4-bit substitution boxes with 4-bit differences is known as Differential Cryptanalysis. In this paper a brief review of Differential Cryptanalysis of 4-bit bijective Crypto S-Boxes and a new algorithm to analyze them using 4-bit Boolean Functions (BFs) have been introduced. A brief review of Strict Avalanche Criterion (SAC) of 4-bit bijective Crypto S-Boxes and 4-bit BFs and two new algorithms of both the aforesaid criterions have been introduced in this paper. A New algorithm entitled extended Strict Avalanche Criterion (An Extension to Higher Order SAC or HO-SAC) has also been introduced. A new Analysis of Similarity of extended HO-SAC and Differential Cryptanalysis has also been elaborated in this paper.