Analysis of AES Algorithm Effects on the Diffusion Property

الملخص

In cryptography, confusion and diffusion are two very important characteristics, which must be achieved these characteristics in the ciphertext to obtain a strong cipher and avoid any attacker for attacked. This research aims to propose three methods based on a different sequence of operations of Advanced Encryption Standard (AES) algorithm. In this research is used hamming distance ,which it is a number of different symbols between two strings of equal length, for calculating diffusion. The proposed methods obtained approximately (63 bits) change in each round corresponding to the total number of bits (128 bits), but the standard AES obtains approximately (65 bits). The proposed methods use hamming distance for calculated diffusion property the (49.5%) percentage value of the proposed methods and the (50.9%) percentage value of the standard AES. After testing and verifying, it was concluded the AES algorithm is the best sequence of operations to achieve the best confusion and diffusion of data.