Cryptography and protection of commercial information: method. Lab implementation allowance. Works for studio. Special. 1-40 01 02-02 “Inform” by Sergey Vladimirovich Yarmolik is an indispensable resource for students studying information technology and data security . This manual not only immerses the reader in the world of cryptography, but also offers practical tasks that will help to consolidate theoretical knowledge in practice. In today's world, where information is becoming one of the most valuable resources, issues of its protection and security come to the fore. Yarmolik’s book covers key aspects of cryptography, including basic encryption algorithms, authentication methods, and data protection. The author shares his knowledge and experience, making complex concepts accessible and understandable to students. Each laboratory work is carefully thought out to help the reader not only master the theory, but also apply it in real-world scenarios. This tutorial will be especially useful for technical students interested in information security, as well as for those who are planning a career in the field of IT. If you want to deepen your knowledge in the field of information security, understand how modern encryption systems work, and learn how to apply this knowledge in practice, then this book will be a real find for you. The topics covered in the book cover a wide range of issues, including the basics of information theory, cryptographic protection methods, and the legal and ethical aspects of working with commercial information. Yarmolik raises important questions about how to protect data from unauthorized access, as well as how to ensure their integrity and accessibility. These topics are relevant not only for students, but also for practitioners working in the field of information security. The author's style is clear and structured, which makes the material easy to perceive. Yarmolik uses many examples and illustrations, which allows you to better understand complex concepts. In addition, it actively incorporates into the text practical recommendations that will help readers successfully cope with laboratory work and projects. Sergey Vladimirovich Yarmolik is a well-known specialist in the field of information technology and security, the author of several textbooks and scientific articles . His works are popular among students and teachers, which indicates a high level of trust in his knowledge and experience. If you are interested in topics related to information security, encryption and data security, then you can find a lot of useful information in his other works. The book "Cryptography and protection of commercial information" will be an excellent addition to the library of any student or specialist who seeks to deepen his knowledge in the field of information security. It will not only help you master the necessary skills, but also inspire you to further explore this fascinating and important area. If you are looking for a quality tutorial that combines theory and practice, then this edition is definitely worth your attention.