The book "Streaming cryptosystems: a textbook on the courses "Coding and protection of information", "Fundamentals of cryptology" for students of the specialty" by Salomatin S . B. is an indispensable resource for anyone interested in modern methods of information protection and the basics of cryptology This handbook not only covers the theoretical aspects of cryptography, but also offers practical solutions that make it relevant for both students and information security professionals. The book focuses on stream cryptosystems one of the key components of modern encryption. Salomatin examines in detail their structure, principles of operation and application in real conditions. The reader will be able to learn about how stream ciphers ensure data security, as well as what algorithms and protocols are used in modern systems. The author emphasizes the importance of understanding these mechanisms in light of the growing threats to cybersecurity, which makes the book especially relevant in our time. This book will be of interest not only to students studying in specialties related to information technology, but also to specialists working in the field of information security, as well as to anyone who wants to understand more deeply how modern encryption systems work. If you are interested in topics related to data security, cryptography, or just want to expand your knowledge in this area, then “Flow Cryptosystems” will be a real find for you. Salomatin, as an author, is known for his deep understanding of the subject and ability to convey complex ideas in simple and accessible language. His writing style combines scientific rigor and practical focus, which allows the reader not only to assimilate theoretical concepts, but also to apply them in practice. In this manual, he uses many examples and illustrations, which makes the material more clear and understandable. The book covers many important topics, such as encryption algorithms, methods of analysis of cryptosystems, as well as modern trends in the field of cryptography. Salomatin emphasizes that with the rapid development of technologies and an increase in the amount of information transmitted, knowledge of the basics of cryptology becomes necessary to ensure data security. It also discusses topical issues such as protection against attacks and vulnerabilities, making the book particularly valuable for cybersecurity professionals. If you are looking for literature that will help you understand the intricacies of cryptography and teach you how to apply the knowledge you have gained in practice, then Streaming Cryptosystems is exactly what you need. The book will be a great addition to your learning process or professional activities, and will also help you stay one step ahead in a world where information is the new currency. Thus, Salomatin’s “Streaming Cryptosystems” is not just a textbook, but a real find for anyone who wants to understand the world of cryptography and information security more deeply. Do not miss the opportunity to immerse yourself in a fascinating and important world where every word can be the key to the security of your data.