G.I. Khoruzhenko - Post-graduate Student, at the Department of Cryptology and Discrete Mathematics in NRNU MEPhI. E-mail: georgy.khoruzhenko@gmail.com

S.S. Volokitin - Post-graduate Student. Chair of the Information Security and Communications Network, South-West State University (Kursk). E-mail: volokitinss@gmail.com V.P. Dobritsa - Dr. Sc. (Phys.-Math), Professor, Chair of the Information Security and Communications Net-work, South-West State University (Kursk). E-mail: dobritsa@mail.ru