Modeling of the equations for the method of linear cryptoanalysis of modern block codes

This paper discusses the modeling of equations systems for linear cryptanalysis of modern block cipher algorithm. The authors examine the main moments of estimation the strength of modern block ciphers using the method of linear cryptanalysis. On the example of a simplified model of encryption the authors considered approaches to creation effective linear equations possessing maximum efficiency. It is shown how to obtain the final linear analog for the n-round encryption algorithm. If the cipher allows the construction of an efficient equations system, it allows you to perform a successful attack in order to find the secret key.