Abstract: Cryptanalysis is a very important challenge that faces
cryptographers. It has several types that should be well studied by
cryptographers to be able to design cryptosystem more secure and
able to resist any type of attacks. This paper introduces six types of
attacks: Linear, Differential , Linear-Differential, Truncated
differential Impossible differential attack and Algebraic attacks.
In this paper, algebraic attack is used to formulate the substitution
box(S-box) of a block cipher to system of nonlinear equations and
solve this system by using a classical method called Grobner
Bases . By Solving these equations, we made algebraic attack on
S-box.