Interest in steganography has emerged in the last decade due to the widespread use of multimedia technologies. Steganography methods make it possible not only to transfer data covertly, but also to solve the problems of noise-resistant authentication, protection of information from unauthorized copying, tracking the distribution of information over communication networks, and searching for information in multimedia databases.In Russian, several topics were devoted to steganography review articles in a special issue of the Confident magazine - and nothing more. This book aims to fill this gap. It summarizes the latest research results of foreign scientists, considers both theoretical and practical aspects of steganography, classifies stegosystems and embedding methods, examines in detail the issues of increasing the throughput of a stegochannel, ensuring the stability and invisibility of implementation, and provides more than 50 data embedding algorithms.The book is intended for students, graduate students, researchers studying the issues of information security, as well as for design engineers of information security tools. It will also arouse undoubted interest among specialists in the field of information theory and digital signal processing.