"Algebraic Cryptanalysis" is a specialized book that bridges the gap between theoretical training in cryptography and the practical application of cryptanalytic literature. It is divided into three main parts: the first part deals with transforming a cipher into a system of equations, while the second part focuses on linear algebra over finite fields. The third part is dedicated to solving polynomial systems of equations and provides an overview of the methods used in practice, including SAT solvers and the techniques of Nicolas Courtois. This book is aimed at advanced students of computer science and mathematics, as well as researchers in the fields of applied abstract algebra and algebraic geometry who are interested in practical topics. It serves both as a textbook and as a reference work for self-directed study.