If the history of mankind could be presented in the form of a spy novel, then the main characters of this work would undoubtedly be cryptographers and cryptanalysts.  The first are specialists who masterfully master the art of encoding messages.  The second are geniuses of hacking and decryption, called hackers in computer slang.  The history of the rivalry between cryptographers and cryptanalysts is as old as the world. Evolving along with the development of high technologies, the craft of encryption has reached in the 21st century the farthest frontier of modern science - quantum mechanics.  And although the object of coding is usually text, the tool of coders’ work has been and remains mathematics.  This book is an attempt to tell the reader the history of encryption through the prism of the development of mathematical thought.